AIM 3/29/18 iii Table of Contents Section 4. Special Use Airspace Paragraph Page 3-4-1. General 3-4-1 ............................................................ 3-4-2. Prohibited Areas 3-4-1 .................................................... 3-4-3. Restricted Areas 3-4-1 .................................................... 3-4-4. Warning Areas 3-4-1 ...................................................... 3-4-5. Military Operations Areas 3-4-2 ............................................ 3-4-6. Alert Areas 3-4-2 ......................................................... 3-4-7. Controlled Firing Areas 3-4-2 .............................................. 3-4-8. National Security Areas 3-4-2 .............................................. 3-4-9. Obtaining Special Use Airspace Status 3-4-2 ................................. Section 5. Other Airspace Areas 3-5-1. Airport Advisory/Information Services 3-5-1 .................................. 3-5-2. Military Training Routes 3-5-1 ............................................. 3-5-3. Temporary Flight Restrictions 3-5-2 ......................................... 3-5-4. Parachute Jump Aircraft Operations 3-5-5 ................................... 3-5-5. Published VFR Routes 3-5-5 ............................................... 3-5-6. Terminal Radar Service Area (TRSA) 3-5-9 .................................. 3-5-7. Special Air Traffic Rules (SATR) and Special Flight Rules Area (SFRA) 3-5-9 ..... 3-5-8. Weather Reconnaissance Area (WRA) 3-5-9 ................................. Chapter 4. Air Traffic Control Section 1. Services Available to Pilots 4-1-1. Air Route Traffic Control Centers 4-1-1 ..................................... 4-1-2. Control Towers 4-1-1 ..................................................... 4-1-3. Flight Service Stations 4-1-1 ............................................... 4-1-4. Recording and Monitoring 4-1-1 ............................................ 4-1-5. Communications Release of IFR Aircraft Landing at an Airport Without an Operating Control Tower 4-1-1 ....................................... 4-1-6. Pilot Visits to Air Traffic Facilities 4-1-1 ..................................... 4-1-7. Operation Rain Check 4-1-2 ............................................... 4-1-8. Approach Control Service for VFR Arriving Aircraft 4-1-2 ..................... 4-1-9. Traffic Advisory Practices at Airports Without Operating Control Towers 4-1-2 .... 4-1-10. IFR Approaches/Ground Vehicle Operations 4-1-6 ........................... 4-1-11. Designated UNICOM/MULTICOM Frequencies 4-1-6 ....................... 4-1-12. Use of UNICOM for ATC Purposes 4-1-7 ................................... 4-1-13. Automatic Terminal Information Service (ATIS) 4-1-7 ........................ 4-1-14. Automatic Flight Information Service (AFIS) - Alaska FSSs Only 4-1-8 ......... 4-1-15. Radar Traffic Information Service 4-1-9 .................................... 4-1-16. Safety Alert 4-1-10 ....................................................... 4-1-17. Radar Assistance to VFR Aircraft 4-1-11 .................................... 4-1-18. Terminal Radar Services for VFR Aircraft 4-1-12 ............................. 4-1-19. Tower En Route Control (TEC) 4-1-14 ...................................... 4-1-20. Transponder Operation 4-1-15 ............................................. 4-1-21. Airport Reservation Operations and Special Traffic Management Programs 4-1-18 . 4-1-22. Requests for Waivers and Authorizations from Title 14, Code of Federal Regulations (14 CFR) 4-1-20 ............................................ 4-1-23. Weather System Processor 4-1-20 ...........................................
Centers are established primarily to provide air trafficservice to aircraft operating on IFR flight plans withincontrolled airspace, and principally during theen route phase of flight.
4−1−2. Control Towers
Towers have been established to provide for a safe,orderly and expeditious flow of traffic on and in thevicinity of an airport. When the responsibility hasbeen so delegated, towers also provide for theseparation of IFR aircraft in the terminal areas.
REFERENCE−AIM, Paragraph 5−4−3 , Approach Control
4−1−3. Flight Service Stations
Flight Service Stations (FSSs) are air trafficfacilities which provide pilot briefings, flight planprocessing, en route flight advisories, search andrescue services, and assistance to lost aircraft andaircraft in emergency situations. FSSs also relay ATCclearances, process Notices to Airmen, broadcastaviation weather and aeronautical information, andadvise Customs and Border Protection of transborderflights. In Alaska, designated FSSs also provideTWEB recordings, take weather observations, andprovide Airport Advisory Services (AAS).
4−1−4. Recording and Monitoring
a. Calls to air traffic control (ATC) facilities(ARTCCs, Towers, FSSs, Central Flow, andOperations Centers) over radio and ATC operationaltelephone lines (lines used for operational purposessuch as controller instructions, briefings, opening andclosing flight plans, issuance of IFR clearances andamendments, counter hijacking activities, etc.) maybe monitored and recorded for operational uses suchas accident investigations, accident prevention,search and rescue purposes, specialist training and
evaluation, and technical evaluation and repair ofcontrol and communications systems.
b. Where the public access telephone is recorded,a beeper tone is not required. In place of the “beep”tone the FCC has substituted a mandatory require-ment that persons to be recorded be given notice theyare to be recorded and give consent. Notice is givenby this entry, consent to record is assumed by theindividual placing a call to the operational facility.
4−1−5. Communications Release of IFRAircraft Landing at an Airport Without anOperating Control Tower
Aircraft operating on an IFR flight plan, landing at anairport without an operating control tower will beadvised to change to the airport advisory frequencywhen direct communications with ATC are no longerrequired. Towers and centers do not have nontowerairport traffic and runway in use information. Theinstrument approach may not be aligned with therunway in use; therefore, if the information has notalready been obtained, pilots should make anexpeditious change to the airport advisory frequencywhen authorized.REFERENCE−AIM, Paragraph 5−4−4 , Advance Information on Instrument Approach
4−1−6. Pilot Visits to Air Traffic Facilities
Pilots are encouraged to participate in local pilot/airtraffic control outreach activities. However, due tosecurity and workload concerns, requests for airtraffic facility visits may not always be approved.Therefore, visit requests should be submitted throughthe air traffic facility as early as possible. Pilotsshould contact the facility and advise them of thenumber of persons in the group, the time and date ofthe proposed visit, and the primary interest of thegroup. The air traffic facility will provide furtherinstructions if a request can be approved.REFERENCE−FAA Order 1600.69, FAA Facility Security Management Program
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4−1−7. Operation Rain Check
Operation Rain Check is a program designed andmanaged by local air traffic control facilitymanagement. Its purpose is to familiarize pilots andaspiring pilots with the ATC system, its functions,responsibilities and benefits.
REFERENCE−FAA Order JO 7210.3, Paragraph 4−2−2, Pilot EducationFAA Order 1600.69, FAA Facility Security Management Program
4−1−8. Approach Control Service for VFRArriving Aircraft
a. Numerous approach control facilities haveestablished programs for arriving VFR aircraft tocontact approach control for landing information.This information includes: wind, runway, andaltimeter setting at the airport of intended landing.This information may be omitted if contained in theAutomatic Terminal Information Service (ATIS)broadcast and the pilot states the appropriate ATIScode.
NOTE−Pilot use of “have numbers” does not indicate receipt of theATIS broadcast. In addition, the controller will providetraffic advisories on a workload permitting basis.
b. Such information will be furnished upon initialcontact with concerned approach control facility. Thepilot will be requested to change to the towerfrequency at a predetermined time or point, to receivefurther landing information.
c. Where available, use of this procedure will nothinder the operation of VFR flights by requiringexcessive spacing between aircraft or deviousrouting.
d. Compliance with this procedure is notmandatory but pilot participation is encouraged.
REFERENCE−AIM, Paragraph 4−1−18 , Terminal Radar Services for VFR Aircraft
NOTE−Approach control services for VFR aircraft are normallydependent on ATC radar. These services are not availableduring periods of a radar outage. Approach controlservices for VFR aircraft are limited when CENRAP is inuse.
4−1−9. Traffic Advisory Practices atAirports Without Operating Control Towers
(See TBL 4−1−1.)
a. Airport Operations Without OperatingControl Tower
1. There is no substitute for alertness while inthe vicinity of an airport. It is essential that pilots bealert and look for other traffic and exchange trafficinformation when approaching or departing anairport without an operating control tower. This is ofparticular importance since other aircraft may nothave communication capability or, in some cases,pilots may not communicate their presence orintentions when operating into or out of such airports.To achieve the greatest degree of safety, it is essentialthat all radio-equipped aircraft transmit/receive on acommon frequency identified for the purpose ofairport advisories.
2. An airport may have a full or part-time toweror FSS located on the airport, a full or part-timeUNICOM station or no aeronautical station at all.There are three ways for pilots to communicate theirintention and obtain airport/traffic information whenoperating at an airport that does not have an operatingtower: by communicating with an FSS, a UNICOMoperator, or by making a self-announce broadcast.
NOTE−FSS airport advisories are available only in Alaska.
3. Many airports are now providing completelyautomated weather, radio check capability and airportadvisory information on an automated UNICOMsystem. These systems offer a variety of features,typically selectable by microphone clicks, on theUNICOM frequency. Availability of the automatedUNICOM will be published in the Chart SupplementU.S. and approach charts.
b. Communicating on a Common Frequency
1. The key to communicating at an airportwithout an operating control tower is selection of thecorrect common frequency. The acronym CTAFwhich stands for Common Traffic AdvisoryFrequency, is synonymous with this program. ACTAF is a frequency designated for the purpose ofcarrying out airport advisory practices whileoperating to or from an airport without an operatingcontrol tower. The CTAF may be a UNICOM,MULTICOM, FSS, or tower frequency and isidentified in appropriate aeronautical publications.
NOTE−FSS frequencies are available only in Alaska.
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TBL 4−1−1Summary of Recommended Communication Procedures
Communication/Broadcast Procedures
Facility at Airport Frequency Use Outbound InboundPractice
InstrumentApproach
1. UNICOM (No Tower orFSS)
Communicate with UNICOMstation on published CTAFfrequency (122.7; 122.8; 122.725;122.975; or 123.0). If unable tocontact UNICOM station, useself-announce procedures onCTAF.
Before taxiing andbefore taxiing onthe runway fordeparture.
10 miles out.Enteringdownwind, base,and final. Leavingthe runway.
2. No Tower, FSS, orUNICOM
Self-announce on MULTICOMfrequency 122.9.
Before taxiing andbefore taxiing onthe runway fordeparture.
10 miles out.Enteringdownwind, base,and final. Leavingthe runway.
Departing finalapproach fix(name) or on finalapproach segmentinbound.
3. No Tower in operation,FSS open (Alaska only)
Communicate with FSS on CTAFfrequency.
Before taxiing andbefore taxiing onthe runway fordeparture.
10 miles out.Enteringdownwind, base,and final. Leavingthe runway.
Approach com-pleted/terminated.
4. FSS Closed (No Tower) Self-announce on CTAF. Before taxiing andbefore taxiing onthe runway fordeparture.
10 miles out.Enteringdownwind, base,and final. Leavingthe runway.
5. Tower or FSS not inoperation
Self-announce on CTAF. Before taxiing andbefore taxiing onthe runway fordeparture.
10 miles out.Enteringdownwind, base,and final. Leavingthe runway.
6. Designated CTAF Area(Alaska Only)
Self-announce on CTAFdesignated on chart or ChartSupplement Alaska.
Before taxiing andbefore taxiing onthe runway fordeparture untilleaving designatedarea.
When enteringdesignated CTAFarea.
2. CTAF (Alaska Only). In Alaska, a CTAFmay also be designated for the purpose of carrying outadvisory practices while operating in designatedareas with a high volume of VFR traffic.
3. The CTAF frequency for a particular airportor area is contained in the Chart Supplement U.S.,Chart Supplement Alaska, Alaska Terminal Publica-tion, Instrument Approach Procedure Charts, andInstrument Departure Procedure (DP) Charts. Also,the CTAF frequency can be obtained by contactingany FSS. Use of the appropriate CTAF, combinedwith a visual alertness and application of thefollowing recommended good operating practices,will enhance safety of flight into and out of alluncontrolled airports.
c. Recommended Traffic Advisory Practices
1. Pilots of inbound traffic should monitor andcommunicate as appropriate on the designated CTAFfrom 10 miles to landing. Pilots of departing aircraftshould monitor/communicate on the appropriatefrequency from start-up, during taxi, and until10 miles from the airport unless the CFRs or localprocedures require otherwise.
2. Pilots of aircraft conducting other thanarriving or departing operations at altitudes normallyused by arriving and departing aircraft shouldmonitor/communicate on the appropriate frequencywhile within 10 miles of the airport unless required todo otherwise by the CFRs or local procedures. Such
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operations include parachute jumping/dropping, enroute, practicing maneuvers, etc.
3. In Alaska, pilots of aircraft conducting otherthan arriving or departing operations in designatedCTAF areas should monitor/communicate on theappropriate frequency while within the designatedarea, unless required to do otherwise by CFRs or localprocedures. Such operations include parachutejumping/dropping, en route, practicing maneuvers,etc.
d. Airport Advisory/Information ServicesProvided by a FSS
1. There are two advisory type servicesprovided at selected airports.
(a) Local Airport Advisory (LAA) is avail-able only in Alaska and provided at airports that havea FSS physically located on the airport, which doesnot have a control tower or where the tower isoperated on a part−time basis. The CTAF for LAAairports is disseminated in the appropriate aeronauti-cal publications.
(b) Remote Airport Information Ser-vice (RAIS) is provided in support of special eventsat nontowered airports by request from the airportauthority.
2. In communicating with a CTAF FSS, checkthe airport’s automated weather and establishtwo−way communications before transmitting out-bound/inbound intentions or information. Aninbound aircraft should initiate contact approximate-ly 10 miles from the airport, reporting aircraftidentification and type, altitude, location relative tothe airport, intentions (landing or over flight),possession of the automated weather, and requestairport advisory or airport information service. Adeparting aircraft should initiate contact beforetaxiing, reporting aircraft identification and type,VFR or IFR, location on the airport, intentions,direction of take−off, possession of the automatedweather, and request airport advisory or informationservice. Also, report intentions before taxiing ontothe active runway for departure. If you must changefrequencies for other service after initial report toFSS, return to FSS frequency for traffic update.
(a) Inbound
EXAMPLE−Vero Beach radio, Centurion Six Niner Delta Delta isten miles south, two thousand, landing Vero Beach. I havethe automated weather, request airport advisory.
(b) Outbound
EXAMPLE−Vero Beach radio, Centurion Six Niner Delta Delta, readyto taxi to runway 22, VFR, departing to the southwest. Ihave the automated weather, request airport advisory.
3. Airport advisory service includes winddirection and velocity, favored or designated runway,altimeter setting, known airborne and ground traffic,NOTAMs, airport taxi routes, airport traffic patterninformation, and instrument approach procedures.These elements are varied so as to best serve thecurrent traffic situation. Some airport managers havespecified that under certain wind or other conditionsdesignated runways be used. Pilots should advise theFSS of the runway they intend to use.
CAUTION−All aircraft in the vicinity of an airport may not be incommunication with the FSS.
e. Information Provided by AeronauticalAdvisory Stations (UNICOM)
1. UNICOM is a nongovernment air/groundradio communication station which may provideairport information at public use airports where thereis no tower or FSS.
2. On pilot request, UNICOM stations mayprovide pilots with weather information, winddirection, the recommended runway, or othernecessary information. If the UNICOM frequency isdesignated as the CTAF, it will be identified inappropriate aeronautical publications.
f. Unavailability of Information from FSS orUNICOM
Should LAA by an FSS or Aeronautical AdvisoryStation UNICOM be unavailable, wind and weatherinformation may be obtainable from nearbycontrolled airports via Automatic Terminal Informa-tion Service (ATIS) or Automated WeatherObserving System (AWOS) frequency.
g. Self-Announce Position and/or Intentions
1. General. Self-announce is a procedurewhereby pilots broadcast their position or intendedflight activity or ground operation on the designatedCTAF. This procedure is used primarily at airportswhich do not have an FSS on the airport. The
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self-announce procedure should also be used if a pilotis unable to communicate with the FSS on thedesignated CTAF. Pilots stating, “Traffic in the area,please advise” is not a recognized Self−AnnouncePosition and/or Intention phrase and should not beused under any condition.
2. If an airport has a tower and it is temporarilyclosed, or operated on a part-time basis and there is noFSS on the airport or the FSS is closed, use the CTAFto self-announce your position or intentions.
3. Where there is no tower, FSS, or UNICOMstation on the airport, use MULTICOM frequency122.9 for self-announce procedures. Such airportswill be identified in appropriate aeronauticalinformation publications.
4. Practice Approaches. Pilots conductingpractice instrument approaches should be particular-ly alert for other aircraft that may be departing in theopposite direction. When conducting any practiceapproach, regardless of its direction relative to otherairport operations, pilots should make announce-ments on the CTAF as follows:
(a) Departing the final approach fix, inbound(nonprecision approach) or departing the outermarker or fix used in lieu of the outer marker, inbound(precision approach);
(b) Established on the final approach segmentor immediately upon being released by ATC;
(c) Upon completion or termination of theapproach; and
(d) Upon executing the missed approachprocedure.
5. Departing aircraft should always be alert forarrival aircraft coming from the opposite direction.
6. Recommended self-announce phraseologies:It should be noted that aircraft operating to or fromanother nearby airport may be making self-announcebroadcasts on the same UNICOM or MULTICOMfrequency. To help identify one airport from another,the airport name should be spoken at the beginningand end of each self-announce transmission.
(a) Inbound
EXAMPLE−Strawn traffic, Apache Two Two Five Zulu, (position),(altitude), (descending) or entering downwind/base/final(as appropriate) runway one seven full stop, touch−and−
go, Strawn.Strawn traffic Apache Two Two Five Zulu clear of runwayone seven Strawn.
(b) Outbound
EXAMPLE−Strawn traffic, Queen Air Seven One Five Five Bravo(location on airport) taxiing to runway two six Strawn.Strawn traffic, Queen Air Seven One Five Five Bravodeparting runway two six. Departing the pattern to the(direction), climbing to (altitude) Strawn.
(c) Practice Instrument Approach
EXAMPLE−Strawn traffic, Cessna Two One Four Three Quebec(position from airport) inbound descending through(altitude) practice (name of approach) approach runwaythree five Strawn.Strawn traffic, Cessna Two One Four Three Quebecpractice (type) approach completed or terminated runwaythree five Strawn.
h. UNICOM Communications Procedures
1. In communicating with a UNICOM station,the following practices will help reduce frequencycongestion, facilitate a better understanding of pilotintentions, help identify the location of aircraft in thetraffic pattern, and enhance safety of flight:
(a) Select the correct UNICOM frequency.
(b) State the identification of the UNICOMstation you are calling in each transmission.
(c) Speak slowly and distinctly.
(d) Report approximately 10 miles from theairport, reporting altitude, and state your aircraft type,aircraft identification, location relative to the airport,state whether landing or overflight, and request windinformation and runway in use.
(e) Report on downwind, base, and finalapproach.
(f) Report leaving the runway.
2. Recommended UNICOM phraseologies:
(a) Inbound
PHRASEOLOGY−FREDERICK UNICOM CESSNA EIGHT ZERO ONETANGO FOXTROT 10 MILES SOUTHEASTDESCENDING THROUGH (altitude) LANDINGFREDERICK, REQUEST WIND AND RUNWAYINFORMATION FREDERICK.FREDERICK TRAFFIC CESSNA EIGHT ZERO ONETANGO FOXTROT ENTERING DOWNWIND/BASE/
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FINAL (as appropriate) FOR RUNWAY ONE NINER (fullstop/touch−and−go) FREDERICK.FREDERICK TRAFFIC CESSNA EIGHT ZERO ONETANGO FOXTROT CLEAR OF RUNWAY ONE NINERFREDERICK.
(b) Outbound
PHRASEOLOGY−FREDERICK UNICOM CESSNA EIGHT ZERO ONETANGO FOXTROT (location on airport) TAXIING TORUNWAY ONE NINER, REQUEST WIND AND TRAFFICINFORMATION FREDERICK. FREDERICK TRAFFIC CESSNA EIGHT ZERO ONETANGO FOXTROT DEPARTING RUNWAY ONE NINER.“REMAINING IN THE PATTERN” OR “DEPARTINGTHE PATTERN TO THE (direction) (as appropriate)”FREDERICK.
4−1−10. IFR Approaches/Ground VehicleOperations
a. IFR Approaches. When operating in accor-dance with an IFR clearance and ATC approves achange to the advisory frequency, make anexpeditious change to the CTAF and employ therecommended traffic advisory procedures.
b. Ground Vehicle Operation. Airport groundvehicles equipped with radios should monitor theCTAF frequency when operating on the airportmovement area and remain clear of runways/taxi-ways being used by aircraft. Radio transmissionsfrom ground vehicles should be confined tosafety-related matters.
c. Radio Control of Airport Lighting Systems.Whenever possible, the CTAF will be used to controlairport lighting systems at airports without operatingcontrol towers. This eliminates the need for pilots tochange frequencies to turn the lights on and allows acontinuous listening watch on a single frequency. TheCTAF is published on the instrument approach chartand in other appropriate aeronautical informationpublications. For further details concerning radiocontrolled lights, see AC 150/5340−27, Air−to−Ground Radio Control of Airport Lighting Systems.
4−1−11. Designated UNICOM/MULTICOMFrequencies
Frequency use
a. The following listing depicts UNICOM andMULTICOM frequency uses as designated by theFederal Communications Commission (FCC). (See TBL 4−1−2.)
TBL 4−1−2Unicom/Multicom Frequency Usage
Use Frequency
Airports without an operatingcontrol tower.
122.700122.725122.800122.975123.000123.050123.075
(MULTICOM FREQUENCY)Activities of a temporary, seasonal,emergency nature or search andrescue, as well as, airports with notower, FSS, or UNICOM.
122.900
(MULTICOM FREQUENCY)Forestry management and firesuppression, fish and gamemanagement and protection, andenvironmental monitoring andprotection.
122.925
Airports with a control tower orFSS on airport.
122.950
NOTE−1. In some areas of the country, frequency interferencemay be encountered from nearby airports using the sameUNICOM frequency. Where there is a problem, UNICOMoperators are encouraged to develop a “least interfer-ence” frequency assignment plan for airports concernedusing the frequencies designated for airports withoutoperating control towers. UNICOM licensees areencouraged to apply for UNICOM 25 kHz spaced channelfrequencies. Due to the extremely limited number offrequencies with 50 kHz channel spacing, 25 kHz channelspacing should be implemented. UNICOM licensees maythen request FCC to assign frequencies in accordance withthe plan, which FCC will review and consider for approval.
2. Wind direction and runway information may not beavailable on UNICOM frequency 122.950.
b. The following listing depicts other frequencyuses as designated by the Federal CommunicationsCommission (FCC). (See TBL 4−1−3.)
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TBL 4−1−3Other Frequency Usage Designated by FCC
Use Frequency
Air-to-air communication (private fixed wing aircraft).
a. ATIS is the continuous broadcast of recordednoncontrol information in selected high activityterminal areas. Its purpose is to improve controllereffectiveness and to relieve frequency congestion byautomating the repetitive transmission of essentialbut routine information. The information is continu-ously broadcast over a discrete VHF radio frequencyor the voice portion of a local NAVAID. Arrival ATIStransmissions on a discrete VHF radio frequency areengineered according to the individual facilityrequirements, which would normally be a protectedservice volume of 20 NM to 60 NM from the ATISsite and a maximum altitude of 25,000 feet AGL. Inthe case of a departure ATIS, the protected servicevolume cannot exceed 5 NM and 100 feet AGL. Atmost locations, ATIS signals may be received on thesurface of the airport, but local conditions may limitthe maximum ATIS reception distance and/oraltitude. Pilots are urged to cooperate in the ATISprogram as it relieves frequency congestion onapproach control, ground control, and local controlfrequencies. The Chart Supplement U.S. indicatesairports for which ATIS is provided.
b. ATIS information includes:
1. Airport/facility name
2. Phonetic letter code
3. Time of the latest weather sequence (UTC)
4. Weather information consisting of:
(a) Wind direction and velocity
(b) Visibility
(c) Obstructions to vision
(d) Present weather consisting of: sky condi-tion, temperature, dew point, altimeter, a densityaltitude advisory when appropriate, and otherpertinent remarks included in the official weatherobservation
5. Instrument approach and runway in use.
The ceiling/sky condition, visibility, and obstructionsto vision may be omitted from the ATIS broadcast ifthe ceiling is above 5,000 feet and the visibility ismore than 5 miles. The departure runway will only begiven if different from the landing runway except atlocations having a separate ATIS for departure. Thebroadcast may include the appropriate frequency andinstructions for VFR arrivals to make initial contactwith approach control. Pilots of aircraft arriving ordeparting the terminal area can receive thecontinuous ATIS broadcast at times when cockpitduties are least pressing and listen to as many repeatsas desired. ATIS broadcast must be updated upon thereceipt of any official hourly and special weather. Anew recording will also be made when there is achange in other pertinent data such as runway change,instrument approach in use, etc.
EXAMPLE−Dulles International information Sierra. One four zerozero zulu. Wind three five zero at eight. Visibility one zero.Ceiling four thousand five hundred broken. Temperaturethree four. Dew point two eight. Altimeter three zero onezero. ILS runway one right approach in use. Departingrunway three zero. Advise on initial contact you haveinformation sierra.
c. Pilots should listen to ATIS broadcastswhenever ATIS is in operation.
d. Pilots should notify controllers on initialcontact that they have received the ATIS broadcast byrepeating the alphabetical code word appended to thebroadcast.
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EXAMPLE−“Information Sierra received.”
e. When a pilot acknowledges receipt of the ATISbroadcast, controllers may omit those items con-tained in the broadcast if they are current. Rapidlychanging conditions will be issued by ATC and theATIS will contain words as follows:
EXAMPLE−“Latest ceiling/visibility/altimeter/wind/(other condi-tions) will be issued by approach control/tower.”
NOTE−The absence of a sky condition or ceiling and/or visibilityon ATIS indicates a sky condition or ceiling of 5,000 feet orabove and visibility of 5 miles or more. A remark may bemade on the broadcast, “the weather is better than5000 and 5,” or the existing weather may be broadcast.
f. Controllers will issue pertinent information topilots who do not acknowledge receipt of a broadcastor who acknowledge receipt of a broadcast which isnot current.
g. To serve frequency limited aircraft, FSSs areequipped to transmit on the omnirange frequency atmost en route VORs used as ATIS voice outlets. Suchcommunication interrupts the ATIS broadcast. Pilotsof aircraft equipped to receive on other FSSfrequencies are encouraged to do so in order that theseoverride transmissions may be kept to an absoluteminimum.
h. While it is a good operating practice for pilotsto make use of the ATIS broadcast where it isavailable, some pilots use the phrase “have numbers”in communications with the control tower. Use of thisphrase means that the pilot has received wind,runway, and altimeter information ONLY and thetower does not have to repeat this information. It doesnot indicate receipt of the ATIS broadcast and shouldnever be used for this purpose.
4−1−14. Automatic Flight InformationService (AFIS) − Alaska FSSs Only
a. AFIS is the continuous broadcast of recordednon−control information at airports in Alaska wherean FSS provides local airport advisory service. Itspurpose is to improve FSS specialist efficiency byreducing frequency congestion on the local airportadvisory frequency.
1. The AFIS broadcast will automate therepetitive transmission of essential but routineinformation (for example, weather, favored runway,
braking action, airport NOTAMs, etc.). The informa-tion is continuously broadcast over a discrete VHFradio frequency (usually the ASOS frequency).
2. Use of AFIS is not mandatory, but pilots whochoose to utilize two−way radio communicationswith the FSS are urged to listen to AFIS, as it relievesfrequency congestion on the local airport advisoryfrequency. AFIS broadcasts are updated upon receiptof any official hourly and special weather, andchanges in other pertinent data.
3. When a pilot acknowledges receipt of theAFIS broadcast, FSS specialists may omit thoseitems contained in the broadcast if they are current.When rapidly changing conditions exist, the latestceiling, visibility, altimeter, wind or other conditionsmay be omitted from the AFIS and will be issued bythe FSS specialist on the appropriate radio frequency.
EXAMPLE−“Kotzebue information ALPHA. One six five five zulu.Wind, two one zero at five; visibility two, fog; ceiling onehundred overcast; temperature minus one two, dew pointminus one four; altimeter three one zero five. Altimeter inexcess of three one zero zero, high pressure altimetersetting procedures are in effect. Favored runway two six.Weather in Kotzebue surface area is below V−F−Rminima − an ATC clearance is required. ContactKotzebue Radio on 123.6 for traffic advisories and adviseintentions. Notice to Airmen, Hotham NDB out of service.Transcribed Weather Broadcast out of service. Advise oninitial contact you have ALPHA.”
NOTE−The absence of a sky condition or ceiling and/or visibilityon Alaska FSS AFIS indicates a sky condition or ceiling of5,000 feet or above and visibility of 5 miles or more. Aremark may be made on the broadcast, “the weather isbetter than 5000 and 5.”
b. Pilots should listen to Alaska FSSs AFISbroadcasts whenever Alaska FSSs AFIS is inoperation.NOTE−Some Alaska FSSs are open part time and/or seasonally.
c. Pilots should notify controllers on initialcontact that they have received the Alaska FSSsAFIS broadcast by repeating the phonetic alphabeticletter appended to the broadcast.
EXAMPLE−“Information Alpha received.”
d. While it is a good operating practice for pilotsto make use of the Alaska FSS AFIS broadcast whereit is available, some pilots use the phrase “have
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numbers” in communications with the FSS. Use ofthis phrase means that the pilot has received wind,runway, and altimeter information ONLY and theAlaska FSS does not have to repeat this information.It does not indicate receipt of the AFIS broadcast andshould never be used for this purpose.
4−1−15. Radar Traffic Information Service
This is a service provided by radar ATC facilities.Pilots receiving this service are advised of any radartarget observed on the radar display which may be insuch proximity to the position of their aircraft or itsintended route of flight that it warrants their attention.This service is not intended to relieve the pilot of theresponsibility for continual vigilance to see and avoidother aircraft.
a. Purpose of the Service
1. The issuance of traffic information asobserved on a radar display is based on the principleof assisting and advising a pilot that a particular radartarget’s position and track indicates it may intersect orpass in such proximity to that pilot’s intended flightpath that it warrants attention. This is to alert the pilotto the traffic, to be on the lookout for it, and therebybe in a better position to take appropriate actionshould the need arise.
2. Pilots are reminded that the surveillance radarused by ATC does not provide altitude informationunless the aircraft is equipped with Mode C and theradar facility is capable of displaying altitudeinformation.
b. Provisions of the Service
1. Many factors, such as limitations of the radar,volume of traffic, controller workload and commu-nications frequency congestion, could prevent thecontroller from providing this service. Controllerspossess complete discretion for determining whetherthey are able to provide or continue to provide thisservice in a specific case. The controller’s reasonagainst providing or continuing to provide the servicein a particular case is not subject to question nor needit be communicated to the pilot. In other words, theprovision of this service is entirely dependent uponwhether controllers believe they are in a position toprovide it. Traffic information is routinely providedto all aircraft operating on IFR flight plans exceptwhen the pilot declines the service, or the pilot isoperating within Class A airspace. Traffic informa-
tion may be provided to flights not operating on IFRflight plans when requested by pilots of such flights.NOTE−Radar ATC facilities normally display and monitor bothprimary and secondary radar when it is available, exceptthat secondary radar may be used as the sole displaysource in Class A airspace, and under some circumstancesoutside of Class A airspace (beyond primary coverage andin en route areas where only secondary is available).Secondary radar may also be used outside Class Aairspace as the sole display source when the primary radaris temporarily unusable or out of service. Pilots in contactwith the affected ATC facility are normally advised whena temporary outage occurs; i.e., “primary radar out ofservice; traffic advisories available on transponderaircraft only.” This means simply that only the aircraftwhich have transponders installed and in use will bedepicted on ATC radar indicators when the primary radaris temporarily out of service.
2. When receiving VFR radar advisory service,pilots should monitor the assigned frequency at alltimes. This is to preclude controllers’ concern forradio failure or emergency assistance to aircraft underthe controller’s jurisdiction. VFR radar advisoryservice does not include vectors away fromconflicting traffic unless requested by the pilot. Whenadvisory service is no longer desired, advise thecontroller before changing frequencies and thenchange your transponder code to 1200, if applicable.Pilots should also inform the controller whenchanging VFR cruising altitude. Except in programswhere radar service is automatically terminated, thecontroller will advise the aircraft when radar isterminated.NOTE−Participation by VFR pilots in formal programsimplemented at certain terminal locations constitutes pilotrequest. This also applies to participating pilots at thoselocations where arriving VFR flights are encouraged tomake their first contact with the tower on the approachcontrol frequency.
c. Issuance of Traffic Information. Trafficinformation will include the following concerning atarget which may constitute traffic for an aircraft thatis:
1. Radar identified
(a) Azimuth from the aircraft in terms of the12 hour clock, or
(b) When rapidly maneuvering civil test ormilitary aircraft prevent accurate issuance of trafficas in (a) above, specify the direction from an aircraft’s
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position in terms of the eight cardinal compass points(N, NE, E, SE, S, SW, W, NW). This method must beterminated at the pilot’s request.
(c) Distance from the aircraft in nauticalmiles;
(d) Direction in which the target is proceed-ing; and
(e) Type of aircraft and altitude if known.
EXAMPLE−Traffic 10 o’clock, 3 miles, west-bound (type aircraft andaltitude, if known, of the observed traffic). The altitude maybe known, by means of Mode C, but not verified with thepilot for accuracy. (To be valid for separation purposes byATC, the accuracy of Mode C readouts must be verified.This is usually accomplished upon initial entry into theradar system by a comparison of the readout to pilot statedaltitude, or the field elevation in the case of continuousreadout being received from an aircraft on the airport.)When necessary to issue traffic advisories containingunverified altitude information, the controller will issue theadvisory in the same manner as if it were verified due to theaccuracy of these readouts. The pilot may upon receipt oftraffic information, request a vector (heading) to avoidsuch traffic. The vector will be provided to the extentpossible as determined by the controller provided theaircraft to be vectored is within the airspace under thejurisdiction of the controller.
2. Not radar identified
(a) Distance and direction with respect to afix;
(b) Direction in which the target is proceed-ing; and
(c) Type of aircraft and altitude if known.
EXAMPLE−Traffic 8 miles south of the airport northeastbound, (typeaircraft and altitude if known).
d. The examples depicted in the following figurespoint out the possible error in the position of thistraffic when it is necessary for a pilot to apply driftcorrection to maintain this track. This error could alsooccur in the event a change in course is made at thetime radar traffic information is issued.
FIG 4−1−1Induced Error in Position of Traffic
TRACK
(A) (B)
WIND
TRACK
EXAMPLE−In FIG 4−1−1 traffic information would be issued to thepilot of aircraft “A” as 12 o’clock. The actual position ofthe traffic as seen by the pilot of aircraft “A” would be2 o’clock. Traffic information issued to aircraft “B” wouldalso be given as 12 o’clock, but in this case, the pilot of “B”would see the traffic at 10 o’clock.
FIG 4−1−2Induced Error in Position of Traffic
TRACK
(C)
(D)
WIND TRACK
EXAMPLE−In FIG 4−1−2 traffic information would be issued to thepilot of aircraft “C” as 2 o’clock. The actual position of thetraffic as seen by the pilot of aircraft “C” would be3 o’clock. Traffic information issued to aircraft “D” wouldbe at an 11 o’clock position. Since it is not necessary for thepilot of aircraft “D” to apply wind correction (crab) toremain on track, the actual position of the traffic issuedwould be correct. Since the radar controller can onlyobserve aircraft track (course) on the radar display, trafficadvisories are issued accordingly, and pilots should givedue consideration to this fact when looking for reportedtraffic.
4−1−16. Safety Alert
A safety alert will be issued to pilots of aircraft beingcontrolled by ATC if the controller is aware theaircraft is at an altitude which, in the controller’sjudgment, places the aircraft in unsafe proximity toterrain, obstructions or other aircraft. The provisionof this service is contingent upon the capability of thecontroller to have an awareness of a situationinvolving unsafe proximity to terrain, obstructionsand uncontrolled aircraft. The issuance of a safetyalert cannot be mandated, but it can be expected on a
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reasonable, though intermittent basis. Once the alertis issued, it is solely the pilot’s prerogative todetermine what course of action, if any, to take. Thisprocedure is intended for use in time criticalsituations where aircraft safety is in question.Noncritical situations should be handled via thenormal traffic alert procedures.
a. Terrain or Obstruction Alert
1. Controllers will immediately issue an alert tothe pilot of an aircraft under their control when theyrecognize that the aircraft is at an altitude which, intheir judgment, may be in an unsafe proximity toterrain/obstructions. The primary method of detect-ing unsafe proximity is through Mode C automaticaltitude reports.
EXAMPLE−Low altitude alert Cessna Three Four Juliet, check youraltitude immediately. And if the aircraft is not yet on finalapproach, the MVA (MEA/MIA/MOCA) in your area is sixthousand.
2. Terminal Automated Radar Terminal System(ARTS) IIIA, Common ARTS (to include ARTS IIIEand ARTS IIE) (CARTS), Micro En RouteAutomated Radar Tracking System (MEARTS), andStandard Terminal Automation Replacement System(STARS) facilities have an automated functionwhich, if operating, alerts controllers when a trackedMode C equipped aircraft under their control is belowor is predicted to be below a predetermined minimumsafe altitude. This function, called Minimum SafeAltitude Warning (MSAW), is designed solely as acontroller aid in detecting potentially unsafe aircraftproximity to terrain/obstructions. The ARTS IIIA,CARTS, MEARTS, and STARS facility will, whenMSAW is operating, provide MSAW monitoring forall aircraft with an operating Mode C altitudeencoding transponder that are tracked by the systemand are:
(a) Operating on an IFR flight plan; or
(b) Operating VFR and have requestedMSAW monitoring.
3. Terminal AN/TPX−42A (number beacondecoder system) facilities have an automatedfunction called Low Altitude Alert System (LAAS).Although not as sophisticated as MSAW, LAASalerts the controller when a Mode C transponder
equipped aircraft operating on an IFR flight plan isbelow a predetermined minimum safe altitude.
NOTE−Pilots operating VFR may request MSAW or LAASmonitoring if their aircraft are equipped with Mode Ctransponders.
EXAMPLE−Apache Three Three Papa request MSAW/LAAS.
b. Aircraft Conflict Alert.
1. Controllers will immediately issue an alert tothe pilot of an aircraft under their control if they areaware of another aircraft which is not under theircontrol, at an altitude which, in the controller’sjudgment, places both aircraft in unsafe proximity toeach other. With the alert, when feasible, thecontroller will offer the pilot the position of the trafficif time permits and an alternate course(s) of action.Any alternate course(s) of action the controller mayrecommend to the pilot will be predicated only onother traffic being worked by the controller.
EXAMPLE−American Three, traffic alert, (position of traffic, if timepermits), advise you turn right/left heading (degrees)and/or climb/descend to (altitude) immediately.
4−1−17. Radar Assistance to VFR Aircraft
a. Radar equipped FAA ATC facilities provideradar assistance and navigation service (vectors) toVFR aircraft provided the aircraft can communicatewith the facility, are within radar coverage, and can beradar identified.
b. Pilots should clearly understand that authoriza-tion to proceed in accordance with such radarnavigational assistance does not constitute authoriza-tion for the pilot to violate CFRs. In effect, assistanceprovided is on the basis that navigational guidanceinformation issued is advisory in nature and the job offlying the aircraft safely, remains with the pilot.
c. In many cases, controllers will be unable todetermine if flight into instrument conditions willresult from their instructions. To avoid possiblehazards resulting from being vectored into IFRconditions, pilots should keep controllers advised ofthe weather conditions in which they are operatingand along the course ahead.
d. Radar navigation assistance (vectors) may beinitiated by the controller when one of the followingconditions exist:
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1. The controller suggests the vector and thepilot concurs.
2. A special program has been established andvectoring service has been advertised.
3. In the controller’s judgment the vector isnecessary for air safety.
e. Radar navigation assistance (vectors) and otherradar derived information may be provided inresponse to pilot requests. Many factors, such aslimitations of radar, volume of traffic, communica-tions frequency, congestion, and controller workloadcould prevent the controller from providing it.Controllers have complete discretion for determiningif they are able to provide the service in a particularcase. Their decision not to provide the service in aparticular case is not subject to question.
4−1−18. Terminal Radar Services for VFRAircraft
a. Basic Radar Service:
1. In addition to the use of radar for the controlof IFR aircraft, all commissioned radar facilitiesprovide the following basic radar services for VFRaircraft:
(a) Safety alerts.
(b) Traffic advisories.
(c) Limited radar vectoring (on a workloadpermitting basis).
(d) Sequencing at locations where proce-dures have been established for this purpose and/orwhen covered by a Letter of Agreement.
NOTE−When the stage services were developed, two basic radarservices (traffic advisories and limited vectoring) wereidentified as “Stage I.” This definition became unneces-sary and the term “Stage I” was eliminated from use. Theterm “Stage II” has been eliminated in conjunction withthe airspace reclassification, and sequencing services tolocations with local procedures and/or letters of agreementto provide this service have been included in basic servicesto VFR aircraft. These basic services will still be providedby all terminal radar facilities whether they includeClass B, Class C, Class D or Class E airspace. “Stage III”services have been replaced with “Class B” and “TRSA”service where applicable.
2. Vectoring service may be provided whenrequested by the pilot or with pilot concurrence whensuggested by ATC.
3. Pilots of arriving aircraft should contactapproach control on the publicized frequency andgive their position, altitude, aircraft call sign, typeaircraft, radar beacon code (if transponder equipped),destination, and request traffic information.
4. Approach control will issue wind andrunway, except when the pilot states “have numbers”or this information is contained in the ATIS broadcastand the pilot states that the current ATIS informationhas been received. Traffic information is provided ona workload permitting basis. Approach control willspecify the time or place at which the pilot is tocontact the tower on local control frequency forfurther landing information. Radar service isautomatically terminated and the aircraft need not beadvised of termination when an arriving VFR aircraftreceiving radar services to a tower−controlled airportwhere basic radar service is provided has landed, orto all other airports, is instructed to change to toweror advisory frequency. (See FAA Order JO 7110.65,Air Traffic Control, Paragraph 5−1−13, RadarService Termination.)
5. Sequencing for VFR aircraft is available atcertain terminal locations (see locations listed in theChart Supplement U.S.). The purpose of the serviceis to adjust the flow of arriving VFR and IFR aircraftinto the traffic pattern in a safe and orderly mannerand to provide radar traffic information to departingVFR aircraft. Pilot participation is urged but is notmandatory. Traffic information is provided on aworkload permitting basis. Standard radar separationbetween VFR or between VFR and IFR aircraft is notprovided.
(a) Pilots of arriving VFR aircraft shouldinitiate radio contact on the publicized frequencywith approach control when approximately 25 milesfrom the airport at which sequencing services arebeing provided. On initial contact by VFR aircraft,approach control will assume that sequencing serviceis requested. After radar contact is established, thepilot may use pilot navigation to enter the trafficpattern or, depending on traffic conditions, approachcontrol may provide the pilot with routings or vectorsnecessary for proper sequencing with other partici-pating VFR and IFR traffic en route to the airport.When a flight is positioned behind a precedingaircraft and the pilot reports having that aircraft in
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sight, the pilot will be instructed to follow thepreceding aircraft. THE ATC INSTRUCTION TOFOLLOW THE PRECEDING AIRCRAFT DOESNOT AUTHORIZE THE PILOT TO COMPLYWITH ANY ATC CLEARANCE OR INSTRUC-TION ISSUED TO THE PRECEDING AIRCRAFT.If other “nonparticipating” or “local” aircraft are inthe traffic pattern, the tower will issue a landingsequence. If an arriving aircraft does not want radarservice, the pilot should state “NEGATIVE RADARSERVICE” or make a similar comment, on initialcontact with approach control.
(b) Pilots of departing VFR aircraft areencouraged to request radar traffic information bynotifying ground control on initial contact with theirrequest and proposed direction of flight.
EXAMPLE−Xray ground control, November One Eight Six, Cessna OneSeventy Two, ready to taxi, VFR southbound at 2,500, haveinformation bravo and request radar traffic information.
NOTE−Following takeoff, the tower will advise when to contactdeparture control.
(c) Pilots of aircraft transiting the area and inradar contact/communication with approach controlwill receive traffic information on a controllerworkload permitting basis. Pilots of such aircraftshould give their position, altitude, aircraft call sign,aircraft type, radar beacon code (if transponderequipped), destination, and/or route of flight.
b. TRSA Service (Radar Sequencing andSeparation Service for VFR Aircraft in a TRSA).
1. This service has been implemented at certainterminal locations. The service is advertised in theChart Supplement U.S. The purpose of this service isto provide separation between all participating VFRaircraft and all IFR aircraft operating within theairspace defined as the Terminal Radar Service Area(TRSA). Pilot participation is urged but is notmandatory.
2. If any aircraft does not want the service, thepilot should state “NEGATIVE TRSA SERVICE” ormake a similar comment, on initial contact withapproach control or ground control, as appropriate.
3. TRSAs are depicted on sectional aeronauticalcharts and listed in the Chart Supplement U.S.
4. While operating within a TRSA, pilots areprovided TRSA service and separation as prescribedin this paragraph. In the event of a radar outage,separation and sequencing of VFR aircraft will besuspended as this service is dependent on radar. Thepilot will be advised that the service is not availableand issued wind, runway information, and the time orplace to contact the tower. Traffic information will beprovided on a workload permitting basis.
5. Visual separation is used when prevailingconditions permit and it will be applied as follows:
(a) When a VFR flight is positioned behind apreceding aircraft and the pilot reports having thataircraft in sight, the pilot will be instructed by ATC tofollow the preceding aircraft. Radar service will becontinued to the runway. THE ATC INSTRUCTIONTO FOLLOW THE PRECEDING AIRCRAFTDOES NOT AUTHORIZE THE PILOT TOCOMPLY WITH ANY ATC CLEARANCE ORINSTRUCTION ISSUED TO THE PRECEDINGAIRCRAFT.
(b) If other “nonparticipating” or “local”aircraft are in the traffic pattern, the tower will issuea landing sequence.
(c) Departing VFR aircraft may be asked ifthey can visually follow a preceding departure out ofthe TRSA. The pilot will be instructed to follow theother aircraft provided that the pilot can maintainvisual contact with that aircraft.
6. VFR aircraft will be separated from VFR/IFRaircraft by one of the following:
(a) 500 feet vertical separation.
(b) Visual separation.
(c) Target resolution (a process to ensure thatcorrelated radar targets do not touch).
7. Participating pilots operating VFR in aTRSA:
(a) Must maintain an altitude when assignedby ATC unless the altitude assignment is to maintainat or below a specified altitude. ATC may assignaltitudes for separation that do not conform to14 CFR Section 91.159. When the altitude assign-ment is no longer needed for separation or whenleaving the TRSA, the instruction will be broadcast,“RESUME APPROPRIATE VFR ALTITUDES.”Pilots must then return to an altitude that conforms to14 CFR Section 91.159 as soon as practicable.
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(b) When not assigned an altitude, the pilotshould coordinate with ATC prior to any altitudechange.
8. Within the TRSA, traffic information onobserved but unidentified targets will, to the extentpossible, be provided to all IFR and participatingVFR aircraft. The pilot will be vectored upon requestto avoid the observed traffic, provided the aircraft tobe vectored is within the airspace under thejurisdiction of the controller.
9. Departing aircraft should inform ATC of theirintended destination and/or route of flight andproposed cruising altitude.
10. ATC will normally advise participatingVFR aircraft when leaving the geographical limits ofthe TRSA. Radar service is not automaticallyterminated with this advisory unless specificallystated by the controller.
c. Class C Service. This service provides, inaddition to basic radar service, approved separationbetween IFR and VFR aircraft, and sequencing ofVFR arrivals to the primary airport.
d. Class B Service. This service provides, inaddition to basic radar service, approved separationof aircraft based on IFR, VFR, and/or weight, andsequencing of VFR arrivals to the primary airport(s).
e. PILOT RESPONSIBILITY. THESE SER-VICES ARE NOT TO BE INTERPRETED ASRELIEVING PILOTS OF THEIR RESPONSIBILI-TIES TO SEE AND AVOID OTHER TRAFFICOPERATING IN BASIC VFR WEATHER CONDI-TIONS, TO ADJUST THEIR OPERATIONS ANDFLIGHT PATH AS NECESSARY TO PRECLUDESERIOUS WAKE ENCOUNTERS, TO MAINTAINAPPROPRIATE TERRAIN AND OBSTRUCTIONCLEARANCE, OR TO REMAIN IN WEATHERCONDITIONS EQUAL TO OR BETTER THANTHE MINIMUMS REQUIRED BY 14 CFRSECTION 91.155. WHENEVER COMPLIANCEWITH AN ASSIGNED ROUTE, HEADINGAND/OR ALTITUDE IS LIKELY TO COMPRO-MISE PILOT RESPONSIBILITY RESPECTINGTERRAIN AND OBSTRUCTION CLEARANCE,VORTEX EXPOSURE, AND WEATHER MINI-MUMS, APPROACH CONTROL SHOULD BE SOADVISED AND A REVISED CLEARANCE ORINSTRUCTION OBTAINED.
f. ATC services for VFR aircraft participating interminal radar services are dependent on ATC radar.Services for VFR aircraft are not available duringperiods of a radar outage and are limited duringCENRAP operations. The pilot will be advised whenVFR services are limited or not available.
NOTE−Class B and Class C airspace are areas of regulatedairspace. The absence of ATC radar does not negate therequirement of an ATC clearance to enter Class B airspaceor two way radio contact with ATC to enter Class Cairspace.
4−1−19. Tower En Route Control (TEC)
a. TEC is an ATC program to provide a service toaircraft proceeding to and from metropolitan areas. Itlinks designated Approach Control Areas by anetwork of identified routes made up of the existingairway structure of the National Airspace System.The FAA initiated an expanded TEC program toinclude as many facilities as possible. The program’sintent is to provide an overflow resource in the lowaltitude system which would enhance ATC services.A few facilities have historically allowed turbojets toproceed between certain city pairs, such asMilwaukee and Chicago, via tower en route and theselocations may continue this service. However, theexpanded TEC program will be applied, generally,for nonturbojet aircraft operating at and below10,000 feet. The program is entirely within theapproach control airspace of multiple terminalfacilities. Essentially, it is for relatively short flights.Participating pilots are encouraged to use TEC forflights of two hours duration or less. If longer flightsare planned, extensive coordination may be requiredwithin the multiple complex which could result inunanticipated delays.
b. Pilots requesting TEC are subject to the samedelay factor at the destination airport as other aircraftin the ATC system. In addition, departure and en routedelays may occur depending upon individual facilityworkload. When a major metropolitan airport isincurring significant delays, pilots in the TECprogram may want to consider an alternative airportexperiencing no delay.
c. There are no unique requirements upon pilots touse the TEC program. Normal flight plan filingprocedures will ensure proper flight plan processing.Pilots should include the acronym “TEC” in the
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remarks section of the flight plan when requestingtower en route control.
d. All approach controls in the system may notoperate up to the maximum TEC altitude of10,000 feet. IFR flight may be planned to anysatellite airport in proximity to the major primaryairport via the same routing.
4−1−20. Transponder Operation
a. General
1. Pilots should be aware that proper applicationof transponder operating procedures will provideboth VFR and IFR aircraft with a higher degree ofsafety while operating on the ground and airborne.Transponders with altitude reporting mode turnedON (Mode C or S) substantially increase thecapability of surveillance systems to see an aircraft,thus providing the Air Traffic Controller increasedsituational awareness and the ability to identifypotential traffic conflicts. Even VFR pilots who arenot in contact with ATC will be afforded greaterprotection from IFR aircraft and VFR aircraft whichare receiving traffic advisories. Nevertheless, pilotsshould never relax their visual scanning for otheraircraft.
2. Air Traffic Control Radar Beacon System(ATCRBS) is similar to and compatible with militarycoded radar beacon equipment. Civil Mode A isidentical to military Mode 3.
3. Transponder and ADS-B operations on theground. Civil and military aircraft should operatewith the transponder in the altitude reporting mode(consult the aircraft’s flight manual to determine thespecific transponder position to enable altitudereporting) and ADS-B Out transmissions enabled (ifequipped) at all airports, any time the aircraft ispositioned on any portion of an airport movementarea. This includes all defined taxiways and runways.Pilots must pay particular attention to ATIS andairport diagram notations, General Notes (includedon airport charts), and comply with directionspertaining to transponder and ADS-B usage.Generally, these directions are:
(a) Departures. Select the transponder modewhich allows altitude reporting and enable ADS-B (ifequipped) during pushback or taxi-out from parkingspot. Select TA or TA/RA (if equipped with TCAS)when taking the active runway.
(b) Arrivals. Maintain transponder to thealtitude reporting mode or if TCAS-equipped (TA orTA/RA), select the transponder to altitude reportingmode. Maintain ADS-B Out transmissions (ifequipped) after clearing the active runway. SelectSTBY or OFF for transponder and ADS-B (ifequipped) upon arriving at the aircraft’s parking spotor gate.
4. Transponder and ADS-B Operations inthe Air. EACH PILOT OPERATING AN AIR-CRAFT EQUIPPED WITH AN OPERABLE ATCTRANSPONDER, MAINTAINED IN ACCORD-ANCE WITH 14 CFR SECTION 91.413 OR ADS-BTRANSMITTER, MUST OPERATE THETRANSPONDER/TRANSMITTER, INCLUDINGMODE C/S IF INSTALLED, ON THE APPROPRI-ATE MODE 3/A CODE OR AS ASSIGNED BYATC. EACH PERSON OPERATING AN AIR-CRAFT EQUIPPED WITH ADS-B OUT MUSTOPERATE THIS EQUIPMENT IN THE TRANS-MIT MODE AT ALL TIMES WHILE AIRBORNEUNLESS OTHERWISE REQUESTED BY ATC.
5. A pilot on an IFR flight who elects to cancelthe IFR flight plan prior to reaching destination,should adjust the transponder according to VFRoperations.
6. If entering a U.S. OFFSHORE AIRSPACEAREA from outside the U.S., the pilot should adviseon first radio contact with a U.S. radar ATC facilitythat such equipment is available by adding“transponder” to the aircraft identification.
7. It should be noted by all users of ATCtransponders and ADS−B Out systems that thesurveillance coverage they can expect is limited to“line of sight” with ground radar and ADS−B radiosites. Low altitude or aircraft antenna shielding by theaircraft itself may result in reduced range or loss ofaircraft contact. Surveillance coverage can beimproved by climbing to a higher altitude.
NOTE−Pilots of aircraft equipped with ADS−B should refer toAIM, Automatic Dependent Surveillance − BroadcastServices, Paragraph 4−5−7 , for a complete description ofoperating limitations and procedures.
b. Transponder Code Designation
1. For ATC to utilize one or a combination of the4096 discrete codes FOUR DIGIT CODE DES-IGNATION will be used; for example, code 2100 willbe expressed as TWO ONE ZERO ZERO. Due to the
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operational characteristics of the rapidly expandingautomated ATC system, THE LAST TWO DIGITSOF THE SELECTED TRANSPONDER CODESHOULD ALWAYS READ “00” UNLESS SPECIF-ICALLY REQUESTED BY ATC TO BEOTHERWISE.
c. Automatic Altitude Reporting (Mode C)
1. Some transponders are equipped with aMode C automatic altitude reporting capability. Thissystem converts aircraft altitude in 100 footincrements to coded digital information which istransmitted together with Mode C framing pulses tothe interrogating radar facility. The manner in whichtransponder panels are designed differs, therefore, apilot should be thoroughly familiar with the operationof the transponder so that ATC may realize its fullcapabilities.
2. Adjust transponder to reply on the Mode A/3code specified by ATC and, if equipped, to reply onMode C with altitude reporting capability activatedunless deactivation is directed by ATC or unless theinstalled aircraft equipment has not been tested andcalibrated as required by 14 CFR Section 91.217. Ifdeactivation is required by ATC, turn off the altitudereporting feature of your transponder. An instructionby ATC to “STOP ALTITUDE SQUAWK, ALTI-TUDE DIFFERS (number of feet) FEET,” may be anindication that your transponder is transmittingincorrect altitude information or that you have anincorrect altimeter setting. While an incorrectaltimeter setting has no effect on the Mode C altitudeinformation transmitted by your transponder (trans-ponders are preset at 29.92), it would cause you to flyat an actual altitude different from your assignedaltitude. When a controller indicates that an altitudereadout is invalid, the pilot should initiate a check toverify that the aircraft altimeter is set correctly.
3. Pilots of aircraft with operating Mode Caltitude reporting transponders should report exactaltitude or flight level to the nearest hundred footincrement when establishing initial contact with anATC facility. Exact altitude or flight level reports oninitial contact provide ATC with information that isrequired prior to using Mode C altitude informationfor separation purposes. This will significantlyreduce altitude verification requests.
d. Transponder IDENT Feature
1. The transponder must be operated only asspecified by ATC. Activate the “IDENT” feature onlyupon request of the ATC controller.
e. Code Changes
1. When making routine code changes, pilotsshould avoid inadvertent selection of Codes 7500,7600 or 7700 thereby causing momentary falsealarms at automated ground facilities. For example,when switching from Code 2700 to Code 7200,switch first to 2200 then to 7200, NOT to 7700 andthen 7200. This procedure applies to nondiscreteCode 7500 and all discrete codes in the 7600 and 7700series (i.e., 7600−7677, 7700−7777) which willtrigger special indicators in automated facilities.Only nondiscrete Code 7500 will be decoded as thehijack code.
2. Under no circumstances should a pilot of acivil aircraft operate the transponder on Code 7777.This code is reserved for military interceptoroperations.
3. Military pilots operating VFR or IFR withinrestricted/warning areas should adjust their trans-ponders to Code 4000 unless another code has beenassigned by ATC.
f. Mode C Transponder Requirements
1. Specific details concerning requirements tocarry and operate Mode C transponders, as well asexceptions and ATC authorized deviations from therequirements are found in 14 CFR Section 91.215 and14 CFR Section 99.12.
2. In general, the CFRs require aircraft to beequipped with Mode C transponders when operating:
(a) At or above 10,000 feet MSL over the48 contiguous states or the District of Columbia,excluding that airspace below 2,500 feet AGL;
(b) Within 30 miles of a Class B airspaceprimary airport, below 10,000 feet MSL. Balloons,gliders, and aircraft not equipped with an enginedriven electrical system are excepted from the aboverequirements when operating below the floor ofClass A airspace and/or; outside of a Class B airspaceand below the ceiling of the Class B airspace (or10,000 feet MSL, whichever is lower);
(c) Within and above all Class C airspace, upto 10,000 feet MSL;
(d) Within 10 miles of certain designatedairports, excluding that airspace which is both outside
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the Class D surface area and below 1,200 feet AGL.Balloons, gliders and aircraft not equipped with anengine driven electrical system are excepted from thisrequirement.
3. 14 CFR Section 99.13 requires all aircraftflying into, within, or across the contiguous U.S.ADIZ be equipped with a Mode C or Mode Stransponder. Balloons, gliders and aircraft notequipped with an engine driven electrical system areexcepted from this requirement.
4. Pilots must ensure that their aircraft trans-ponder is operating on an appropriate ATC assignedVFR/IFR code and Mode C when operating in suchairspace. If in doubt about the operational status ofeither feature of your transponder while airborne,contact the nearest ATC facility or FSS and they willadvise you what facility you should contact fordetermining the status of your equipment.
5. In-flight requests for “immediate” deviationfrom the transponder requirement may be approvedby controllers only when the flight will continue IFRor when weather conditions prevent VFR descent andcontinued VFR flight in airspace not affected by theCFRs. All other requests for deviation should bemade by contacting the nearest Flight Service orAir Traffic facility in person or by telephone. Thenearest ARTCC will normally be the controllingagency and is responsible for coordinating requestsinvolving deviations in other ARTCC areas.
g. Transponder Operation Under Visual FlightRules (VFR)
1. Unless otherwise instructed by an ATCfacility, adjust transponder to reply on Mode 3/ACode 1200 regardless of altitude.
NOTE−1. Aircraft not in contact with an ATC facility may squawk1255 in lieu of 1200 while en route to, from, or within thedesignated fire fighting area(s).
2. VFR aircraft which fly authorized SAR missions for theUSAF or USCG may be advised to squawk 1277 in lieu of1200 while en route to, from, or within the designatedsearch area.
3. Gliders not in contact with an ATC facility shouldsquawk 1202 in lieu of 1200.
REFERENCE−FAA Order JO 7110.66, National Beacon Code Allocation Plan.
2. Adjust transponder to reply on Mode C, withaltitude reporting capability activated if the aircraft is
so equipped, unless deactivation is directed by ATCor unless the installed equipment has not been testedand calibrated as required by 14 CFR Section 91.217.If deactivation is required and your transponder is sodesigned, turn off the altitude reporting switch andcontinue to transmit Mode C framing pulses. If thiscapability does not exist, turn off Mode C.
h. Radar Beacon Phraseology
Air traffic controllers, both civil and military, will usethe following phraseology when referring tooperation of the Air Traffic Control Radar BeaconSystem (ATCRBS). Instructions by ATC refer only toMode A/3 or Mode C operation and do not affect theoperation of the transponder on other Modes.
1. SQUAWK (number). Operate radar beacontransponder on designated code in Mode A/3.
2. IDENT. Engage the “IDENT” feature (mili-tary I/P) of the transponder.
3. SQUAWK (number) and IDENT. Operatetransponder on specified code in Mode A/3 andengage the “IDENT” (military I/P) feature.
5. SQUAWK LOW/NORMAL. Operatetransponder on low or normal sensitivity as specified.Transponder is operated in “NORMAL” positionunless ATC specifies “LOW” (“ON” is used insteadof “NORMAL” as a master control label on sometypes of transponders.)
7. STOP ALTITUDE SQUAWK. Turn offaltitude reporting switch and continue transmittingMode C framing pulses. If your equipment does nothave this capability, turn off Mode C.
8. STOP SQUAWK (mode in use). Switch offspecified mode. (Used for military aircraft when thecontroller is unaware of military service require-ments for the aircraft to continue operation on anotherMode.)
9. STOP SQUAWK. Switch off transponder.
10. SQUAWK MAYDAY. Operate transpond-er in the emergency position (Mode A Code 7700 forcivil transponder. Mode 3 Code 7700 and emergencyfeature for military transponder.)
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4−1−18 Services Available to Pilots
11. SQUAWK VFR. Operate radar beacontransponder on Code 1200 in the Mode A/3, or otherappropriate VFR code.
4−1−21. Airport Reservation Operationsand Special Traffic Management Programs
This section describes procedures for obtainingrequired airport reservations at airports designated bythe FAA and for airports operating under SpecialTraffic Management Programs.
a. Slot Controlled Airports.
1. The FAA may adopt rules to require advanceoperations for unscheduled operations at certainairports. In addition to the information in the rulesadopted by the FAA, a listing of the airports andrelevant information will be maintained on the FAAwebsite listed below.
2. The FAA has established an AirportReservation Office (ARO) to receive and processreservations for unscheduled flights at the slotcontrolled airports. The ARO uses the EnhancedComputer Voice Reservation System (e−CVRS) toallocate reservations. Reservations will be availablebeginning 72 hours in advance of the operation at theslot controlled airport. Standby lists are notmaintained. Flights with declared emergencies do notrequire reservations. Refer to the website ortouch−tone phone interface for the current listing ofslot controlled airports, limitations, and reservationprocedures.
NOTE−The web interface/telephone numbers to obtain areservation for unscheduled operations at a slot controlledairport are:1. http://www.fly.faa.gov/ecvrs.2. Touch−tone: 1−800−875−9694 3. Trouble number: 540−422−4246.
3. For more detailed information on operationsand reservation procedures at a Slot ControlledAirport, please see 14 CFR Part 93, Subpart K – HighDensity Traffic Airports.
b. Special Traffic Management Programs(STMP).
1. Special procedures may be established whena location requires special traffic handling toaccommodate above normal traffic demand (forexample, the Indianapolis 500, Super Bowl, etc.) orreduced airport capacity (for example, airportrunway/taxiway closures for airport construction).The special procedures may remain in effect until theproblem has been resolved or until local trafficmanagement procedures can handle the situation anda need for special handling no longer exists.
2. There will be two methods available forobtaining slot reservations through theATCSCC: the web interface and the touch−toneinterface. If these methods are used, a NOTAM willbe issued relaying the website address and toll freetelephone number. Be sure to check currentNOTAMs to determine: what airports are includedin the STMP, the dates and times reservations arerequired, the time limits for reservation requests, thepoint of contact for reservations, and any otherinstructions.
NOTE−The telephone numbers/web address to obtain a STMP slotare:1.Touch−tone interface: 1−800−875−9755.2. Web interface: www.fly.faa.gov.3. Trouble number: 540−422−4246.
c. Users may contact the ARO at (540) 422−4246if they have a problem making a reservation or havea question concerning the slot controlled airport/STMP regulations or procedures.
d. Making Reservations.
1. Internet Users. Detailed information andUser Instruction Guides for using the Web interfaceto the reservation systems are available on thewebsites for the slot controlled airports (e−CVRS),http://www.fly.faa.gov/ecvrs; and STMPs(e−STMP), http://www.fly.faa.gov/estmp.
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4−1−19Services Available to Pilots
2. Telephone users. When using the telephoneto make a reservation, you are prompted for input ofinformation about what you wish to do. All input isaccomplished using the keypad on the telephone. Theonly problem with a telephone is that most keys havea letter and number associated with them. When thesystem asks for a date or time, it is expecting an inputof numbers. A problem arises when entering anaircraft call sign or tail number. The system does notdetect if you are entering a letter (alpha character) ora number. Therefore, when entering an aircraft callsign or tail number two keys are used to representeach letter or number. When entering a number,precede the number you wish by the number 0 (zero)i.e., 01, 02, 03, 04, . . .. If you wish to enter a letter, firstpress the key on which the letter appears and then
press 1, 2, or 3, depending upon whether the letter youdesire is the first, second, or third letter on that key.For example, to enter the letter “N” first press the“6” key because “N” is on that key, then press the“2” key because the letter “N” is the second letter onthe “6” key. Since there are no keys for the letters “Q”and “Z” e−CVRS pretends they are on the number“1” key. Therefore, to enter the letter “Q”, press 11,and to enter the letter “Z” press 12.
NOTE−Users are reminded to enter the “N” character with theirtail numbers. (See TBL 4−1−4.)
3. For additional helpful key entries, seeTBL 4−1−5.
# After entering a call sign/tail number, depressing the “pound key” (#) twice will indicate the end of theentry.
*2 Will take the user back to the start of the process.*3 Will repeat the call sign/tail number used in a previous reservation.*5 Will repeat the previous question.*8 Tutorial Mode: In the tutorial mode each prompt for input includes a more detailed description of what
is expected as input. *8 is a toggle on/off switch. If you are in tutorial mode and enter *8, you will returnto the normal mode.
*0 Expert Mode: In the expert mode each prompt for input is brief with little or no explanation. Expertmode is also on/off toggle.
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4−1−20 Services Available to Pilots
4−1−22. Requests for Waivers andAuthorizations from Title 14, Code ofFederal Regulations (14 CFR)
a. Requests for a Certificate of Waiver orAuthorization (FAA Form 7711−2), or requests forrenewal of a waiver or authorization, may be acceptedby any FAA facility and will be forwarded, ifnecessary, to the appropriate office having waiverauthority.
b. The grant of a Certificate of Waiver orAuthorization from 14 CFR constitutes relief fromspecific regulations, to the degree and for the periodof time specified in the certificate, and does not waiveany state law or local ordinance. Should the proposedoperations conflict with any state law or localordinance, or require permission of local authoritiesor property owners, it is the applicant’s responsibilityto resolve the matter. The holder of a waiver isresponsible for compliance with the terms of thewaiver and its provisions.
c. A waiver may be canceled at any time by theAdministrator, the person authorized to grant thewaiver, or the representative designated to monitor aspecific operation. In such case either written noticeof cancellation, or written confirmation of a verbalcancellation will be provided to the holder.
4−1−23. Weather System Processor
The Weather System Processor (WSP) was devel-oped for use in the National Airspace System toprovide weather processor enhancements to selectedAirport Surveillance Radar (ASR)−9 facilities. TheWSP provides Air Traffic with warnings ofhazardous wind shear and microbursts. The WSP alsoprovides users with terminal area 6−level weather,storm cell locations and movement, as well as thelocation and predicted future position and intensity ofwind shifts that may affect airport operations.
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4−2−1Radio Communications Phraseology
Section 2. Radio Communications Phraseology and Techniques
4−2−1. General
a. Radio communications are a critical link in theATC system. The link can be a strong bond betweenpilot and controller or it can be broken with surprisingspeed and disastrous results. Discussion hereinprovides basic procedures for new pilots and alsohighlights safe operating concepts for all pilots.
b. The single, most important thought in pilot-controller communications is understanding. It isessential, therefore, that pilots acknowledge eachradio communication with ATC by using theappropriate aircraft call sign. Brevity is important,and contacts should be kept as brief as possible, butcontrollers must know what you want to do beforethey can properly carry out their control duties. Andyou, the pilot, must know exactly what the controllerwants you to do. Since concise phraseology may notalways be adequate, use whatever words arenecessary to get your message across. Pilots are tomaintain vigilance in monitoring air traffic controlradio communications frequencies for potentialtraffic conflicts with their aircraft especially whenoperating on an active runway and/or whenconducting a final approach to landing.
c. All pilots will find the Pilot/Controller Glossaryvery helpful in learning what certain words or phrasesmean. Good phraseology enhances safety and is themark of a professional pilot. Jargon, chatter, and“CB” slang have no place in ATC communications.The Pilot/Controller Glossary is the same glossaryused in FAA Order JO 7110.65, Air Traffic Control.We recommend that it be studied and reviewed fromtime to time to sharpen your communication skills.
4−2−2. Radio Technique
a. Listen before you transmit. Many times you canget the information you want through ATIS or bymonitoring the frequency. Except for a few situationswhere some frequency overlap occurs, if you hearsomeone else talking, the keying of your transmitterwill be futile and you will probably jam theirreceivers causing them to repeat their call. If you have
just changed frequencies, pause, listen, and make surethe frequency is clear.
b. Think before keying your transmitter. Knowwhat you want to say and if it is lengthy; e.g., a flightplan or IFR position report, jot it down.
c. The microphone should be very close to yourlips and after pressing the mike button, a slight pausemay be necessary to be sure the first word istransmitted. Speak in a normal, conversational tone.
d. When you release the button, wait a fewseconds before calling again. The controller or FSSspecialist may be jotting down your number, lookingfor your flight plan, transmitting on a differentfrequency, or selecting the transmitter for yourfrequency.
e. Be alert to the sounds or the lack of sounds inyour receiver. Check your volume, recheck yourfrequency, and make sure that your microphone is notstuck in the transmit position. Frequency blockagecan, and has, occurred for extended periods of timedue to unintentional transmitter operation. This typeof interference is commonly referred to as a “stuckmike,” and controllers may refer to it in this mannerwhen attempting to assign an alternate frequency. Ifthe assigned frequency is completely blocked by thistype of interference, use the procedures described foren route IFR radio frequency outage to establish orreestablish communications with ATC.
f. Be sure that you are within the performancerange of your radio equipment and the ground stationequipment. Remote radio sites do not always transmitand receive on all of a facility’s available frequencies,particularly with regard to VOR sites where you canhear but not reach a ground station’s receiver.Remember that higher altitudes increase the range ofVHF “line of sight” communications.
4−2−3. Contact Procedures
a. Initial Contact.
1. The terms initial contact or initial callupmeans the first radio call you make to a given facilityor the first call to a different controller or FSSspecialist within a facility. Use the following format:
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4−2−2 Radio Communications Phraseology
(a) Name of the facility being called;
(b) Your full aircraft identification as filed inthe flight plan or as discussed in paragraph 4−2−4,Aircraft Call Signs;
(c) When operating on an airport surface,state your position.
(d) The type of message to follow or yourrequest if it is short; and
(e) The word “Over” if required.
EXAMPLE−1. “New York Radio, Mooney Three One One Echo.”2. “Columbia Ground, Cessna Three One Six ZeroFoxtrot, south ramp, I−F−R Memphis.”3. “Miami Center, Baron Five Six Three Hotel, requestV−F−R traffic advisories.”
2. Many FSSs are equipped with RemoteCommunications Outlets (RCOs) and can transmit onthe same frequency at more than one location. Thefrequencies available at specific locations areindicated on charts above FSS communicationsboxes. To enable the specialist to utilize the correcttransmitter, advise the location and the frequency onwhich you expect a reply.
EXAMPLE−St. Louis FSS can transmit on frequency 122.3 at eitherFarmington, Missouri, or Decatur, Illinois, if you are in thevicinity of Decatur, your callup should be “Saint Louisradio, Piper Six Niner Six Yankee, receiving Decatur OneTwo Two Point Three.”
3. If radio reception is reasonably assured,inclusion of your request, your position or altitude,and the phrase “(ATIS) Information Charliereceived” in the initial contact helps decrease radiofrequency congestion. Use discretion; do notoverload the controller with information unneeded orsuperfluous. If you do not get a response from theground station, recheck your radios or use anothertransmitter, but keep the next contact short.
EXAMPLE−“Atlanta Center, Duke Four One Romeo, request V−F−Rtraffic advisories, Twenty Northwest Rome, seven thousandfive hundred, over.”
b. Initial Contact When Your Transmitting andReceiving Frequencies are Different.
1. If you are attempting to establish contact witha ground station and you are receiving on a differentfrequency than that transmitted, indicate the VORname or the frequency on which you expect a reply.
Most FSSs and control facilities can transmit onseveral VOR stations in the area. Use the appropriateFSS call sign as indicated on charts.
EXAMPLE−New York FSS transmits on the Kennedy, the Hampton, andthe Calverton VORTACs. If you are in the Calverton area,your callup should be “New York radio, Cessna Three OneSix Zero Foxtrot, receiving Calverton V−O−R, over.”
2. If the chart indicates FSS frequencies abovethe VORTAC or in the FSS communications boxes,transmit or receive on those frequencies nearest yourlocation.
3. When unable to establish contact and youwish to call any ground station, use the phrase “ANYRADIO (tower) (station), GIVE CESSNA THREEONE SIX ZERO FOXTROT A CALL ON(frequency) OR (V−O−R).” If an emergency exists oryou need assistance, so state.
c. Subsequent Contacts and Responses toCallup from a Ground Facility.
Use the same format as used for the initial contactexcept you should state your message or request withthe callup in one transmission. The ground stationname and the word “Over” may be omitted if themessage requires an obvious reply and there is nopossibility for misunderstandings. You shouldacknowledge all callups or clearances unless thecontroller or FSS specialist advises otherwise. Thereare some occasions when controllers must issuetime-critical instructions to other aircraft, and theymay be in a position to observe your response, eithervisually or on radar. If the situation demands yourresponse, take appropriate action or immediatelyadvise the facility of any problem. Acknowledge withyour aircraft identification, either at the beginning orat the end of your transmission, and one of the words“Wilco,” “Roger,” “Affirmative,” “Negative,” orother appropriate remarks; e.g., “PIPER TWO ONEFOUR LIMA, ROGER.” If you have been receivingservices; e.g., VFR traffic advisories and you areleaving the area or changing frequencies, advise theATC facility and terminate contact.
d. Acknowledgement of Frequency Changes.
1. When advised by ATC to change frequencies,acknowledge the instruction. If you select the newfrequency without an acknowledgement, the control-ler’s workload is increased because there is no way ofknowing whether you received the instruction or havehad radio communications failure.
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4−2−3Radio Communications Phraseology
2. At times, a controller/specialist may beworking a sector with multiple frequency assign-ments. In order to eliminate unnecessary verbiageand to free the controller/specialist for higher prioritytransmissions, the controller/specialist may requestthe pilot “(Identification), change to my frequency123.4.” This phrase should alert the pilot that thecontroller/specialist is only changing frequencies, notcontroller/specialist, and that initial callup phraseolo-gy may be abbreviated.
EXAMPLE−“United Two Twenty−Two on one two three point four” or“one two three point four, United Two Twenty−Two.”
e. Compliance with Frequency Changes.
When instructed by ATC to change frequencies,select the new frequency as soon as possible unlessinstructed to make the change at a specific time, fix,or altitude. A delay in making the change could resultin an untimely receipt of important information. Ifyou are instructed to make the frequency change at aspecific time, fix, or altitude, monitor the frequencyyou are on until reaching the specified time, fix, oraltitudes unless instructed otherwise by ATC.
1. Improper use of call signs can result in pilotsexecuting a clearance intended for another aircraft.Call signs should never be abbreviated on an initialcontact or at any time when other aircraft call signshave similar numbers/sounds or identical letters/number; e.g., Cessna 6132F, Cessna 1622F,Baron 123F, Cherokee 7732F, etc.
EXAMPLE−Assume that a controller issues an approach clearance toan aircraft at the bottom of a holding stack and an aircraftwith a similar call sign (at the top of the stack)acknowledges the clearance with the last two or threenumbers of the aircraft’s call sign. If the aircraft at thebottom of the stack did not hear the clearance andintervene, flight safety would be affected, and there wouldbe no reason for either the controller or pilot to suspect thatanything is wrong. This kind of “human factors” error canstrike swiftly and is extremely difficult to rectify.
2. Pilots, therefore, must be certain that aircraftidentification is complete and clearly identified
before taking action on an ATC clearance. ATCspecialists will not abbreviate call signs of air carrieror other civil aircraft having authorized call signs.ATC specialists may initiate abbreviated call signs ofother aircraft by using the prefix and the last threedigits/letters of the aircraft identification aftercommunications are established. The pilot may usethe abbreviated call sign in subsequent contacts withthe ATC specialist. When aware of similar/identicalcall signs, ATC specialists will take action tominimize errors by emphasizing certain numbers/let-ters, by repeating the entire call sign, by repeating theprefix, or by asking pilots to use a different call signtemporarily. Pilots should use the phrase “VERIFYCLEARANCE FOR (your complete call sign)” ifdoubt exists concerning proper identity.
3. Civil aircraft pilots should state the aircrafttype, model or manufacturer’s name, followed by thedigits/letters of the registration number. When theaircraft manufacturer’s name or model is stated, theprefix “N” is dropped; e.g., Aztec Two Four Six FourAlpha.
EXAMPLE−1. Bonanza Six Five Five Golf.
2. Breezy Six One Three Romeo Experimental (omit“Experimental” after initial contact).
4. Air Taxi or other commercial operators nothaving FAA authorized call signs should prefix theirnormal identification with the phonetic word“Tango.”
EXAMPLE−Tango Aztec Two Four Six Four Alpha.
5. Air carriers and commuter air carriers havingFAA authorized call signs should identify themselvesby stating the complete call sign (using group formfor the numbers) and the word “super” or “heavy” ifappropriate.
EXAMPLE−1. United Twenty−Five Heavy.
2. Midwest Commuter Seven Eleven.
6. Military aircraft use a variety of systemsincluding serial numbers, word call signs, andcombinations of letters/numbers. Examples includeArmy Copter 48931; Air Force 61782; REACH31792; Pat 157; Air Evac 17652; Navy Golf AlfaKilo 21; Marine 4 Charlie 36, etc.
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4−2−4 Radio Communications Phraseology
b. Air Ambulance Flights.
Because of the priority afforded air ambulance flightsin the ATC system, extreme discretion is necessarywhen using the term “MEDEVAC.” It is onlyintended for those missions of an urgent medicalnature and to be utilized only for that portion of theflight requiring expeditious handling. When re-quested by the pilot, necessary notification toexpedite ground handling of patients, etc., is providedby ATC; however, when possible, this informationshould be passed in advance through non−ATCcommunications systems.
1. Civilian air ambulance flights responding tomedical emergencies (first call to an accident scene,carrying patients, organ donors, organs, or otherurgently needed lifesaving medical material) will beexpedited by ATC when necessary. When expedi-tious handling is necessary, include the word“MEDEVAC” in the flight plan per paragraphs 5−1−8and 5−1−9. In radio communications, use the callsign“MEDEVAC,” followed by the aircraft registra-tion letters/numbers.
EXAMPLE−MEDEVAC Two Six Four Six.
2. Similar provisions have been made for the useof “AIR EVAC” and “HOSP” by air ambulanceflights, except that these flights will receive priorityhandling only when specifically requested.
3. Air carrier and air taxi flights responding tomedical emergencies will also be expedited by ATCwhen necessary. The nature of these medicalemergency flights usually concerns the transporta-tion of urgently needed lifesaving medical materialsor vital organs. IT IS IMPERATIVE THAT THECOMPANY/PILOT DETERMINE, BY THENATURE/URGENCY OF THE SPECIFICMEDICAL CARGO, IF PRIORITY ATC ASSIST-ANCE IS REQUIRED. Pilots must include the word“MEDEVAC” in the flight plan per paragraphs 5−1−8and 5−1−9, and use the call sign “MEDEVAC,”followed by the company name and flight number forall transmissions when expeditious handling isrequired. It is important for ATC to be aware of“MEDEVAC” status, and it is the pilot’s responsibil-ity to ensure that this information is provided to ATC.
EXAMPLE−MEDEVAC Delta Thirty−Seven.
c. Student Pilots Radio Identification.
1. The FAA desires to help student pilots inacquiring sufficient practical experience in theenvironment in which they will be required tooperate. To receive additional assistance whileoperating in areas of concentrated air traffic, studentpilots need only identify themselves as a student pilotduring their initial call to an FAA radio facility.
EXAMPLE−Dayton tower, Fleetwing One Two Three Four, studentpilot.
2. This special identification will alert FAAATC personnel and enable them to provide studentpilots with such extra assistance and consideration asthey may need. It is recommended that student pilotsidentify themselves as such, on initial contact witheach clearance delivery prior to taxiing, groundcontrol, tower, approach and departure controlfrequency, or FSS contact.
4−2−5. Description of Interchange orLeased Aircraft
a. Controllers issue traffic information based onfamiliarity with airline equipment and color/markings. When an air carrier dispatches a flightusing another company’s equipment and the pilotdoes not advise the terminal ATC facility, the possibleconfusion in aircraft identification can compromisesafety.
b. Pilots flying an “interchange” or “leased”aircraft not bearing the colors/markings of thecompany operating the aircraft should inform theterminal ATC facility on first contact the name of theoperating company and trip number, followed by thecompany name as displayed on the aircraft, andaircraft type.
EXAMPLE−Air Cal Three Eleven, United (interchange/lease),Boeing Seven Two Seven.
4−2−6. Ground Station Call Signs
Pilots, when calling a ground station, should beginwith the name of the facility being called followed bythe type of the facility being called as indicated inTBL 4−2−1.
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4−2−5Radio Communications Phraseology
TBL 4−2−1Calling a Ground Station
Facility Call Sign
Airport UNICOM “Shannon UNICOM”FAA Flight Service Station “Chicago Radio”Airport Traffic ControlTower
“Augusta Tower”
Clearance Delivery Position(IFR)
“Dallas ClearanceDelivery”
Ground Control Position inTower
“Miami Ground”
Radar or NonradarApproach Control Position
“Oklahoma CityApproach”
Radar Departure ControlPosition
“St. Louis Departure”
FAA Air Route TrafficControl Center
“Washington Center”
4−2−7. Phonetic Alphabet
The International Civil Aviation Organization(ICAO) phonetic alphabet is used by FAA personnelwhen communications conditions are such that theinformation cannot be readily received without theiruse. ATC facilities may also request pilots to usephonetic letter equivalents when aircraft with similarsounding identifications are receiving communica-tions on the same frequency. Pilots should use thephonetic alphabet when identifying their aircraftduring initial contact with air traffic control facilities.Additionally, use the phonetic equivalents for singleletters and to spell out groups of letters or difficultwords during adverse communications conditions.(See TBL 4−2−2.)
TBL 4−2−2Phonetic Alphabet/Morse Code
Character Morse Code TelephonyPhonic
(Pronunciation)
A ! " Alfa (AL−FAH)
B " ! ! ! Bravo (BRAH−VOH)
C " ! " ! Charlie (CHAR−LEE) or(SHAR−LEE)
D " ! ! Delta (DELL−TAH)
E ! Echo (ECK−OH)
F ! ! " ! Foxtrot (FOKS−TROT)
G " " ! Golf (GOLF)
H ! ! ! ! Hotel (HOH−TEL)
I ! ! India (IN−DEE−AH)
J ! " " " Juliett (JEW−LEE−ETT)
K " ! " Kilo (KEY−LOH)
L ! " ! ! Lima (LEE−MAH)
M " " Mike (MIKE)
N " ! November (NO−VEM−BER)
O " " " Oscar (OSS−CAH)
P ! " " ! Papa (PAH−PAH)
Q " " ! " Quebec (KEH−BECK)
R ! " ! Romeo (ROW−ME−OH)
S ! ! ! Sierra (SEE−AIR−RAH)
T " Tango (TANG−GO)
U ! ! " Uniform (YOU−NEE−FORM) or(OO−NEE−FORM)
V ! ! ! " Victor (VIK−TAH)
W ! " " Whiskey (WISS−KEY)
X " ! ! " Xray (ECKS−RAY)
Y " ! " " Yankee (YANG−KEY)
Z " " ! ! Zulu (ZOO−LOO)
1 ! " " " " One (WUN)
2 ! ! " " " Two (TOO)
3 ! ! ! " " Three (TREE)
4 ! ! ! ! " Four (FOW−ER)
5 ! ! ! ! ! Five (FIFE)
6 " ! ! ! ! Six (SIX)
7 " " ! ! ! Seven (SEV−EN)
8 " " " ! ! Eight (AIT)
9 " " " " ! Nine (NIN−ER)
0 " " " " " Zero (ZEE−RO)
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4−2−6 Radio Communications Phraseology
4−2−8. Figures
a. Figures indicating hundreds and thousands inround number, as for ceiling heights, and upper windlevels up to 9,900 must be spoken in accordance withthe following.
EXAMPLE−1. 500 five hundred. . . . . . . .
2. 4,500 four thousand five hundred. . . . . .
b. Numbers above 9,900 must be spoken byseparating the digits preceding the word “thousand.”
EXAMPLE−1. 10,000 one zero thousand. . . . .
2. 13,500 one three thousand five hundred. . . . .
c. Transmit airway or jet route numbers as follows.
EXAMPLE−1. V12 Victor Twelve. . . . . . .
2. J533 J Five Thirty−Three. . . . . . .
d. All other numbers must be transmitted bypronouncing each digit.
EXAMPLE−10 one zero. . . . . . . . . . .
e. When a radio frequency contains a decimalpoint, the decimal point is spoken as “POINT.”
EXAMPLE−122.1 one two two point one. . . . . . . . .
NOTE−ICAO procedures require the decimal point be spoken as“DECIMAL.” The FAA will honor such usage by militaryaircraft and all other aircraft required to use ICAOprocedures.
4−2−9. Altitudes and Flight Levels
a. Up to but not including 18,000 feet MSL, statethe separate digits of the thousands plus the hundredsif appropriate.
EXAMPLE−1. 12,000 one two thousand. . . . .
2. 12,500 one two thousand five hundred. . . . .
b. At and above 18,000 feet MSL (FL 180), statethe words “flight level” followed by the separatedigits of the flight level.
5. (Wind direction) 220 wind two two zero. . . . . . . .
4−2−11. Speeds
The separate digits of the speed followed by the word“KNOTS.” Except, controllers may omit the word“KNOTS” when using speed adjustment procedures;e.g., “REDUCE/INCREASE SPEED TO TWOFIVE ZERO.”
EXAMPLE−(Speed) 250 two five zero knots. . . . . . . . . . . . . . . . .(Speed) 190 one niner zero knots. . . . . . . . . . . . . . . . .
The separate digits of the Mach Number preceded by“Mach.”
EXAMPLE−(Mach number) 1.5 Mach one point five. . . . . . . . . . . .(Mach number) 0.64 Mach point six four. . . . . . . . . . .(Mach number) 0.7 Mach point seven. . . . . . . . . . . .
4−2−12. Time
a. FAA uses Coordinated Universal Time (UTC)for all operations. The word “local” or the time zoneequivalent must be used to denote local when localtime is given during radio and telephone communica-tions. The term “Zulu” may be used to denote UTC.
EXAMPLE−0920 UTC zero niner two zero, . . . . . zero one two zero pacific or local, or one twenty AM
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4−2−7Radio Communications Phraseology
b. To convert from Standard Time to CoordinatedUniversal Time:
TBL 4−2−3Standard Time to Coordinated Universal Time
Eastern Standard Time . . . . . . . . .Central Standard Time . . . . . . . . .Mountain Standard Time . . . . . . .Pacific Standard Time . . . . . . . . .Alaska Standard Time . . . . . . . . .Hawaii Standard Time . . . . . . . . .
c. A reference may be made to local daylight orstandard time utilizing the 24−hour clock system. Thehour is indicated by the first two figures and theminutes by the last two figures.
d. Time may be stated in minutes only(two figures) in radiotelephone communicationswhen no misunderstanding is likely to occur.
e. Current time in use at a station is stated in thenearest quarter minute in order that pilots may use thisinformation for time checks. Fractions of a quarterminute less than 8 seconds are stated as the precedingquarter minute; fractions of a quarter minute of8 seconds or more are stated as the succeeding quarterminute.
EXAMPLE−0929:05 time, zero niner two niner. . . . . .0929:10 time, zero niner two niner and . . . . . .
one−quarter
4−2−13. Communications with Tower whenAircraft Transmitter or Receiver or Both areInoperative
a. Arriving Aircraft.
1. Receiver inoperative.
(a) If you have reason to believe your receiveris inoperative, remain outside or above the Class Dsurface area until the direction and flow of traffic hasbeen determined; then, advise the tower of your typeaircraft, position, altitude, intention to land, andrequest that you be controlled with light signals.
REFERENCE−AIM, Paragraph 4−3−13 , Traffic Control Light Signals
(b) When you are approximately 3 to 5 milesfrom the airport, advise the tower of your position andjoin the airport traffic pattern. From this point on,watch the tower for light signals. Thereafter, if acomplete pattern is made, transmit your positiondownwind and/or turning base leg.
2. Transmitter inoperative. Remain outsideor above the Class D surface area until the directionand flow of traffic has been determined; then, join theairport traffic pattern. Monitor the primary localcontrol frequency as depicted on Sectional Charts forlanding or traffic information, and look for a lightsignal which may be addressed to your aircraft.During hours of daylight, acknowledge towertransmissions or light signals by rocking your wings.At night, acknowledge by blinking the landing ornavigation lights. To acknowledge tower transmis-sions during daylight hours, hovering helicopters willturn in the direction of the controlling facility andflash the landing light. While in flight, helicoptersshould show their acknowledgement of receiving atransmission by making shallow banks in oppositedirections. At night, helicopters will acknowledgereceipt of transmissions by flashing either the landingor the search light.
3. Transmitter and receiver inoperative.Remain outside or above the Class D surface areauntil the direction and flow of traffic has beendetermined; then, join the airport traffic pattern andmaintain visual contact with the tower to receive lightsignals. Acknowledge light signals as noted above.
b. Departing Aircraft. If you experience radiofailure prior to leaving the parking area, make everyeffort to have the equipment repaired. If you areunable to have the malfunction repaired, call thetower by telephone and request authorization todepart without two-way radio communications. Iftower authorization is granted, you will be givendeparture information and requested to monitor thetower frequency or watch for light signals asappropriate. During daylight hours, acknowledgetower transmissions or light signals by moving theailerons or rudder. At night, acknowledge by blinkingthe landing or navigation lights. If radio malfunction
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occurs after departing the parking area, watch thetower for light signals or monitor tower frequency.REFERENCE−14 CFR Section 91.125 and 14 CFR Section 91.129.
4−2−14. Communications for VFR Flights
a. FSSs and Supplemental Weather ServiceLocations (SWSL) are allocated frequencies fordifferent functions; for example, in Alaska, certainFSSs provide Local Airport Advisory on 123.6 MHzor other frequencies which can be found in the ChartSupplement U.S. If you are in doubt as to whatfrequency to use, 122.2 MHz is assigned to themajority of FSSs as a common en route simplexfrequency.
NOTE−In order to expedite communications, state the frequencybeing used and the aircraft location during initial callup.
EXAMPLE−Dayton radio, November One Two Three Four Five on onetwo two point two, over Springfield V−O−R, over.
b. Certain VOR voice channels are being utilizedfor recorded broadcasts; i.e., ATIS, HIWAS, etc.These services and appropriate frequencies are listedin the Chart Supplement U.S. On VFR flights, pilotsare urged to monitor these frequencies. When incontact with a control facility, notify the controller ifyou plan to leave the frequency to monitor thesebroadcasts.
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Section 3. Airport Operations
4−3−1. General
Increased traffic congestion, aircraft in climb anddescent attitudes, and pilot preoccupation withcockpit duties are some factors that increase thehazardous accident potential near the airport. Thesituation is further compounded when the weather ismarginal, that is, just meeting VFR requirements.Pilots must be particularly alert when operating in thevicinity of an airport. This section defines some rules,practices, and procedures that pilots should befamiliar with and adhere to for safe airport operations.
4−3−2. Airports with an Operating ControlTower
a. When operating at an airport where trafficcontrol is being exercised by a control tower, pilotsare required to maintain two−way radio contact withthe tower while operating within the Class B, Class C,and Class D surface area unless the tower authorizesotherwise. Initial callup should be made about15 miles from the airport. Unless there is a goodreason to leave the tower frequency before exiting theClass B, Class C, and Class D surface areas, it is agood operating practice to remain on the towerfrequency for the purpose of receiving trafficinformation. In the interest of reducing towerfrequency congestion, pilots are reminded that it isnot necessary to request permission to leave the towerfrequency once outside of Class B, Class C, andClass D surface areas. Not all airports with anoperating control tower will have Class D airspace.These airports do not have weather reporting whichis a requirement for surface based controlledairspace, previously known as a control zone. Thecontrolled airspace over these airports will normallybegin at 700 feet or 1,200 feet above ground level andcan be determined from the visual aeronauticalcharts. Pilots are expected to use good operatingpractices and communicate with the control tower asdescribed in this section.
b. When necessary, the tower controller will issueclearances or other information for aircraft togenerally follow the desired flight path (trafficpatterns) when flying in Class B, Class C, and Class Dsurface areas and the proper taxi routes whenoperating on the ground. If not otherwise authorized
or directed by the tower, pilots of fixed−wing aircraftapproaching to land must circle the airport to the left.Pilots approaching to land in a helicopter must avoidthe flow of fixed−wing traffic. However, in allinstances, an appropriate clearance must be receivedfrom the tower before landing.
FIG 4−3−1Components of a Traffic Pattern
NOTE−This diagram is intended only to illustrate terminologyused in identifying various components of a traffic pattern.It should not be used as a reference or guide on how to entera traffic pattern.
c. The following terminology for the variouscomponents of a traffic pattern has been adopted asstandard for use by control towers and pilots (SeeFIG 4−3−1):
1. Upwind leg. A flight path parallel to thelanding runway in the direction of landing.
2. Crosswind leg. A flight path at right anglesto the landing runway off its takeoff end.
3. Downwind leg. A flight path parallel to thelanding runway in the opposite direction of landing.
4. Base leg. A flight path at right angles to thelanding runway off its approach end and extendingfrom the downwind leg to the intersection of theextended runway centerline.
5. Final approach. A flight path in thedirection of landing along the extended runwaycenterline from the base leg to the runway.
6. Departure. The flight path which beginsafter takeoff and continues straight ahead along theextended runway centerline. The departure climbcontinues until reaching a point at least 1/2 mile
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beyond the departure end of the runway and within300 feet of the traffic pattern altitude.
d. Many towers are equipped with a tower radardisplay. The radar uses are intended to enhance theeffectiveness and efficiency of the local control, ortower, position. They are not intended to provideradar services or benefits to pilots except as they mayaccrue through a more efficient tower operation. Thefour basic uses are:
1. To determine an aircraft’s exact location.This is accomplished by radar identifying the VFRaircraft through any of the techniques available to aradar position, such as having the aircraft squawkident. Once identified, the aircraft’s position andspatial relationship to other aircraft can be quicklydetermined, and standard instructions regarding VFRoperation in Class B, Class C, and Class D surfaceareas will be issued. Once initial radar identificationof a VFR aircraft has been established and theappropriate instructions have been issued, radarmonitoring may be discontinued; the reason beingthat the local controller’s primary means ofsurveillance in VFR conditions is visually scanningthe airport and local area.
2. To provide radar traffic advisories. Radartraffic advisories may be provided to the extent thatthe local controller is able to monitor the radardisplay. Local control has primary control responsibi-lities to the aircraft operating on the runways, whichwill normally supersede radar monitoring duties.
3. To provide a direction or suggestedheading. The local controller may provide pilotsflying VFR with generalized instructions which willfacilitate operations; e.g., “PROCEED SOUTH-WESTBOUND, ENTER A RIGHT DOWNWINDRUNWAY THREE ZERO,” or provide a suggestedheading to establish radar identification or as anadvisory aid to navigation; e.g., “SUGGESTEDHEADING TWO TWO ZERO, FOR RADARIDENTIFICATION.” In both cases, the instructionsare advisory aids to the pilot flying VFR and are notradar vectors.
NOTE−Pilots have complete discretion regarding acceptance ofthe suggested headings or directions and have soleresponsibility for seeing and avoiding other aircraft.
4. To provide information and instructions toaircraft operating within Class B, Class C, and
Class D surface areas. In an example of thissituation, the local controller would use the radar toadvise a pilot on an extended downwind when to turnbase leg.
NOTE−The above tower radar applications are intended toaugment the standard functions of the local controlposition. There is no controller requirement to maintainconstant radar identification. In fact, such a requirementcould compromise the local controller’s ability to visuallyscan the airport and local area to meet FAA responsibilitiesto the aircraft operating on the runways and within theClass B, Class C, and Class D surface areas. Normally,pilots will not be advised of being in radar contact sincethat continued status cannot be guaranteed and since thepurpose of the radar identification is not to establish a linkfor the provision of radar services.
e. A few of the radar equipped towers areauthorized to use the radar to ensure separationbetween aircraft in specific situations, while stillothers may function as limited radar approachcontrols. The various radar uses are strictly a functionof FAA operational need. The facilities may beindistinguishable to pilots since they are all referredto as tower and no publication lists the degree of radaruse. Therefore, when in communication with a towercontroller who may have radar available, do notassume that constant radar monitoring and completeATC radar services are being provided.
4−3−3. Traffic Patterns
a. It is recommended that aircraft enter the airporttraffic pattern at one of the following altitudes listedbelow. These altitudes should be maintained unlessanother traffic pattern altitude is published in theChart Supplement U.S. or unless otherwise requiredby the applicable distance from cloud criteria(14 CFR Section 91.155). (See FIG 4−3−2 andFIG 4−3−3):
1. Propeller−driven aircraft enter the trafficpattern at 1,000 feet above ground level (AGL).
2. Large and turbine−powered aircraft enter thetraffic pattern at an altitude of not less than 1,500 feetAGL or 500 feet above the established patternaltitude.
3. Helicopters operating in the traffic patternmay fly a pattern similar to the fixed−wing aircraftpattern, but at a lower altitude (500 AGL) and closerto the runway. This pattern may be on the oppositeside of the runway from fixed−wing traffic when
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airspeed requires or for practice power−off landings(autorotation) and if local policy permits. Landingsnot to the runway must avoid the flow of fixed wingtraffic.
b. A pilot may vary the size of the traffic patterndepending on the aircraft’s performance characteris-tics. Pilots of en route aircraft should be constantlyalert for aircraft in traffic patterns and avoid theseareas whenever possible.
c. Unless otherwise indicated, all turns in thetraffic pattern must be made to the left, except forhelicopters, as applicable.
d. On Sectional, Aeronautical, and VFR TerminalArea Charts, right traffic patterns are indicated atpublic−use and joint−use airports with the abbrevia-tion “RP” (for Right Pattern), followed by theappropriate runway number(s) at the bottom of theairport data block.
EXAMPLE−RP 9, 18, 22R
NOTE−1. Pilots are encouraged to use the standard trafficpattern. However, those pilots who choose to execute astraight−in approach, maneuvering for and execution ofthe approach should not disrupt the flow of arriving anddeparting traffic. Likewise, pilots operating in the trafficpattern should be alert at all times for aircraft executingstraight−in approaches.REFERENCE−AC 90−66, Recommended Standard Traffic Patterns and Practices forAeronautical Operations at Airports Without Operating Control Towers
2. RP* indicates special conditions exist and refers pilotsto the Chart Supplement U.S.
3. Right traffic patterns are not shown at airports withfull−time control towers.
e. Wind conditions affect all airplanes in varyingdegrees. Figure 4-3-4 is an example of a chart used todetermine the headwind, crosswind, and tailwindcomponents based on wind direction and velocityrelative to the runway. Pilots should refer to similarinformation provided by the aircraft manufacturerwhen determining these wind components.
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FIG 4−3−2Traffic Pattern Operations
Single Runway
EXAMPLE−Key to traffic pattern operations
1. Enter pattern in level flight, abeam the midpoint of therunway, at pattern altitude.
2. Maintain pattern altitude until abeam approach end ofthe landing runway on downwind leg.
3. Complete turn to final at least 1/4 mile from the runway.
4. Continue straight ahead until beyond departure end of
runway.
5. If remaining in the traffic pattern, commence turn tocrosswind leg beyond the departure end of the runwaywithin 300 feet of pattern altitude.
6. If departing the traffic pattern, continue straight out, orexit with a 45 degree turn (to the left when in a left−handtraffic pattern; to the right when in a right−hand trafficpattern) beyond the departure end of the runway, afterreaching pattern altitude.
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FIG 4−3−3Traffic Pattern Operations
Parallel Runways
EXAMPLE−Key to traffic pattern operations
1. Enter pattern in level flight, abeam the midpoint of therunway, at pattern altitude.
2. Maintain pattern altitude until abeam approach end ofthe landing runway on downwind leg.
3. Complete turn to final at least 1/4 mile from the runway.
4. Continue straight ahead until beyond departure end ofrunway.
5. If remaining in the traffic pattern, commence turn to
crosswind leg beyond the departure end of the runwaywithin 300 feet of pattern altitude.
6. If departing the traffic pattern, continue straight out, orexit with a 45 degree turn (to the left when in a left−handtraffic pattern; to the right when in a right−hand trafficpattern) beyond the departure end of the runway, afterreaching pattern altitude.
7. Do not overshoot final or continue on a track which willpenetrate the final approach of the parallel runway.
8. Do not continue on a track which will penetrate thedeparture path of the parallel runway.
4−3−4. Visual Indicators at AirportsWithout an Operating Control Tower
a. At those airports without an operating controltower, a segmented circle visual indicator system, ifinstalled, is designed to provide traffic patterninformation.
REFERENCE−AIM, Paragraph 4−1−9 , Traffic Advisory Practices at Airports WithoutOperating Control Towers
b. The segmented circle system consists of thefollowing components:
1. The segmented circle. Located in a positionaffording maximum visibility to pilots in the air andon the ground and providing a centralized location forother elements of the system.
2. The wind direction indicator. A wind cone,wind sock, or wind tee installed near the operationalrunway to indicate wind direction. The large end ofthe wind cone/wind sock points into the wind as doesthe large end (cross bar) of the wind tee. In lieu of atetrahedron and where a wind sock or wind cone iscollocated with a wind tee, the wind tee may bemanually aligned with the runway in use to indicatelanding direction. These signaling devices may belocated in the center of the segmented circle and maybe lighted for night use. Pilots are cautioned againstusing a tetrahedron to indicate wind direction.
3. The landing direction indicator. A tetrahe-dron is installed when conditions at the airportwarrant its use. It may be used to indicate the directionof landings and takeoffs. A tetrahedron may belocated at the center of a segmented circle and may belighted for night operations. The small end of thetetrahedron points in the direction of landing. Pilotsare cautioned against using a tetrahedron for anypurpose other than as an indicator of landingdirection. Further, pilots should use extreme cautionwhen making runway selection by use of atetrahedron in very light or calm wind conditions asthe tetrahedron may not be aligned with thedesignated calm−wind runway. At airports withcontrol towers, the tetrahedron should only bereferenced when the control tower is not in operation.Tower instructions supersede tetrahedron indica-tions.
4. Landing strip indicators. Installed in pairsas shown in the segmented circle diagram and used toshow the alignment of landing strips.
5. Traffic pattern indicators. Arranged inpairs in conjunction with landing strip indicators andused to indicate the direction of turns when there is avariation from the normal left traffic pattern. (If thereis no segmented circle installed at the airport, trafficpattern indicators may be installed on or near the endof the runway.)
c. Preparatory to landing at an airport without acontrol tower, or when the control tower is not inoperation, pilots should concern themselves with theindicator for the approach end of the runway to beused. When approaching for landing, all turns mustbe made to the left unless a traffic pattern indicatorindicates that turns should be made to the right. If thepilot will mentally enlarge the indicator for therunway to be used, the base and final approach legsof the traffic pattern to be flown immediately becomeapparent. Similar treatment of the indicator at thedeparture end of the runway will clearly indicate thedirection of turn after takeoff.
d. When two or more aircraft are approaching anairport for the purpose of landing, the pilot of theaircraft at the lower altitude has the right−of−wayover the pilot of the aircraft at the higher altitude.However, the pilot operating at the lower altitudeshould not take advantage of another aircraft, whichis on final approach to land, by cutting in front of, orovertaking that aircraft.
4−3−5. Unexpected Maneuvers in theAirport Traffic Pattern
There have been several incidents in the vicinity ofcontrolled airports that were caused primarily byaircraft executing unexpected maneuvers. ATCservice is based upon observed or known traffic andairport conditions. Controllers establish the sequenceof arriving and departing aircraft by requiring them toadjust flight as necessary to achieve proper spacing.These adjustments can only be based on observedtraffic, accurate pilot reports, and anticipated aircraftmaneuvers. Pilots are expected to cooperate so as topreclude disrupting traffic flows or creatingconflicting patterns. The pilot−in−command of anaircraft is directly responsible for and is the finalauthority as to the operation of the aircraft. Onoccasion it may be necessary for pilots to maneuvertheir aircraft to maintain spacing with the traffic theyhave been sequenced to follow. The controller cananticipate minor maneuvering such as shallow “S”turns. The controller cannot, however, anticipate a
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major maneuver such as a 360 degree turn. If a pilotmakes a 360 degree turn after obtaining a landingsequence, the result is usually a gap in the landinginterval and, more importantly, it causes a chainreaction which may result in a conflict with followingtraffic and an interruption of the sequence establishedby the tower or approach controller. Should a pilotdecide to make maneuvering turns to maintainspacing behind a preceding aircraft, the pilot shouldalways advise the controller if at all possible. Exceptwhen requested by the controller or in emergencysituations, a 360 degree turn should never be executedin the traffic pattern or when receiving radar servicewithout first advising the controller.
4−3−6. Use of Runways/Declared Distances
a. Runways are identified by numbers whichindicate the nearest 10-degree increment of theazimuth of the runway centerline. For example,where the magnetic azimuth is 183 degrees, therunway designation would be 18; for a magneticazimuth of 87 degrees, the runway designation wouldbe 9. For a magnetic azimuth ending in the number 5,such as 185, the runway designation could be either18 or 19. Wind direction issued by the tower is alsomagnetic and wind velocity is in knots.
b. Airport proprietors are responsible for takingthe lead in local aviation noise control. Accordingly,they may propose specific noise abatement plans tothe FAA. If approved, these plans are applied in theform of Formal or Informal Runway Use Programsfor noise abatement purposes.REFERENCE−Pilot/Controller Glossary Term− Runway Use Program
1. At airports where no runway use program isestablished, ATC clearances may specify:
(a) The runway most nearly aligned with thewind when it is 5 knots or more;
(b) The “calm wind” runway when wind isless than 5 knots; or
(c) Another runway if operationally advanta-geous.
NOTE−It is not necessary for a controller to specifically inquire ifthe pilot will use a specific runway or to offer a choice ofrunways. If a pilot prefers to use a different runway fromthat specified, or the one most nearly aligned with the wind,the pilot is expected to inform ATC accordingly.
2. At airports where a runway use program isestablished, ATC will assign runways deemed to havethe least noise impact. If in the interest of safety arunway different from that specified is preferred, thepilot is expected to advise ATC accordingly. ATC willhonor such requests and advise pilots when therequested runway is noise sensitive. When use of arunway other than the one assigned is requested, pilotcooperation is encouraged to preclude disruption oftraffic flows or the creation of conflicting patterns.
c. Declared Distances.
1. Declared distances for a runway representthe maximum distances available and suitable formeeting takeoff and landing distance performancerequirements. These distances are determined inaccordance with FAA runway design standards byadding to the physical length of paved runway anyclearway or stopway and subtracting from that sumany lengths necessary to obtain the standard runwaysafety areas, runway object free areas, or runwayprotection zones. As a result of these additions andsubtractions, the declared distances for a runway maybe more or less than the physical length of the runwayas depicted on aeronautical charts and relatedpublications, or available in electronic navigationdatabases provided by either the U.S. Government orcommercial companies.
2. All 14 CFR Part 139 airports report declareddistances for each runway. Other airports may alsoreport declared distances for a runway if necessaryto meet runway design standards or to indicate thepresence of a clearway or stopway. Where reported,declared distances for each runway end arepublished in the Chart Supplement U.S. For runwayswithout published declared distances, the declareddistances may be assumed to be equal to the physicallength of the runway unless there is a displacedlanding threshold, in which case the LandingDistance Available (LDA) is shortened by the amountof the threshold displacement.NOTE−A symbol is shown on U.S. Government charts toindicate that runway declared distance information isavailable (See appropriate Chart Supplement U.S., ChartSupplement Alaska or Pacific).
(a) The FAA uses the following definitionsfor runway declared distances (See FIG 4−3−5):REFERENCE−Pilot/Controller Glossary Terms: “Accelerate−Stop DistanceAvailable,” “Landing Distance Available,” “Takeoff DistanceAvailable,” “Takeoff Run Available,” ” Stopway,” and “Clearway.”
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(1) Takeoff Run Available (TORA) – Therunway length declared available and suitable forthe ground run of an airplane taking off.
The TORA is typically the physical length of therunway, but it may be shorter than the runway lengthif necessary to satisfy runway design standards. Forexample, the TORA may be shorter than the runwaylength if a portion of the runway must be used tosatisfy runway protection zone requirements.
(2) Takeoff Distance Available (TODA) –The takeoff run available plus the length of anyremaining runway or clearway beyond the far end ofthe takeoff run available.
The TODA is the distance declared available forsatisfying takeoff distance requirements for airplaneswhere the certification and operating rules andavailable performance data allow for the considera-tion of a clearway in takeoff performancecomputations.
NOTE−The length of any available clearway will be included in theTODA published in the entry for that runway end within theChart Supplement U.S.
(3) Accelerate−Stop Distance Available(ASDA) – The runway plus stopway length declaredavailable and suitable for the acceleration anddeceleration of an airplane aborting a takeoff.
The ASDA may be longer than the physical length ofthe runway when a stopway has been designatedavailable by the airport operator, or it may be shorterthan the physical length of the runway if necessary touse a portion of the runway to satisfy runway designstandards; for example, where the airport operatoruses a portion of the runway to achieve the runwaysafety area requirement. ASDA is the distance usedto satisfy the airplane accelerate−stop distanceperformance requirements where the certificationand operating rules require accelerate−stop distancecomputations.
NOTE−The length of any available stopway will be included in theASDA published in the entry for that runway end within theChart Supplement U.S.
(4) Landing Distance Available (LDA) −The runway length declared available and suitablefor a landing airplane.
The LDA may be less than the physical length of therunway or the length of the runway remaining beyonda displaced threshold if necessary to satisfy runwaydesign standards;for example, where the airportoperator uses a portion of the runway to achieve therunway safety area requirement.
Although some runway elements (such as stopwaylength and clearway length) may be availableinformation, pilots must use the declared distancesdetermined by the airport operator and not attempt toindependently calculate declared distances byadding those elements to the reported physicallength of the runway.
(b) The airplane operating rules and/or theairplane operating limitations establish minimumdistance requirements for takeoff and landing andare based on performance data supplied in theAirplane Flight Manual or Pilot’s OperatingHandbook. The minimum distances required fortakeoff and landing obtained either in planningprior to takeoff or in performance assessmentsconducted at the time of landing must fall within theapplicable declared distances before the pilot canaccept that runway for takeoff or landing.
(c) Runway design standards may imposerestrictions on the amount of runway available foruse in takeoff and landing that are not apparentfrom the reported physical length of the runway orfrom runway markings and lighting. The runwayelements of Runway Safety Area (RSA), RunwayObject Free Area (ROFA), and Runway ProtectionZone (RPZ) may reduce a runway’s declareddistances to less than the physical length of therunway at geographically constrained airports (SeeFIG 4−3−6). When considering the amount ofrunway available for use in takeoff or landingperformance calculations, the declared distancespublished for a runway must always be used in lieuof the runway’s physical length.
REFERENCE−AC 150/5300−13, Airport Design
(d) While some runway elements associatedwith declared distances may be identifiable throughrunway markings or lighting (for example, adisplaced threshold or a stopway), the individualdeclared distance limits are not marked or otherwiseidentified on the runway. An aircraft is not prohibitedfrom operating beyond a declared distance limitduring the takeoff, landing, or taxi operation
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provided the runway surface is appropriately markedas usable runway (See FIG 4−3−6). The followingexamples clarify the intent of this paragraph.
EXAMPLE−1. The declared LDA for runway 9 must be used whenshowing compliance with the landing distance require-ments of the applicable airplane operating rules and/orairplane operating limitations or when making a beforelanding performance assessment. The LDA is less than thephysical runway length, not only because of the displaced
threshold, but also because of the subtractions necessaryto meet the RSA beyond the far end of the runway. However,during the actual landing operation, it is permissible forthe airplane to roll beyond the unmarked end of the LDA.
2. The declared ASDA for runway 9 must be used whenshowing compliance with the accelerate−stop distancerequirements of the applicable airplane operating rulesand/or airplane operating limitations. The ASDA is lessthan the physical length of the runway due to subtractionsnecessary to achieve the full RSA requirement. However, inthe event of an aborted takeoff, it is permissible for theairplane to roll beyond the unmarked end of the ASDA asit is brought to a full−stop on the remaining usable runway.
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FIG 4−3−5Declared Distances with Full−Standard Runway Safety Areas, Runway Object Free Areas, and Runway
Protection Zones
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FIG 4−3−6Effects of a Geographical Constraint on a Runway’s Declared Distances
NOTE−A runway’s RSA begins a set distance prior to the threshold and will extend a set distance beyond the end of the runwaydepending on the runway’s design criteria. If these required lengths cannot be achieved, the ASDA and/or LDA will bereduced as necessary to obtain the required lengths to the extent practicable.
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4−3−7. Low Level Wind Shear/MicroburstDetection Systems
Low Level Wind Shear Alert System (LLWAS),Terminal Doppler Weather Radar (TDWR), WeatherSystem Processor (WSP), and Integrated TerminalWeather System (ITWS) display information onhazardous wind shear and microburst activity in thevicinity of an airport to air traffic controllers whorelay this information to pilots.
a. LLWAS provides wind shear alert and gust frontinformation but does not provide microburst alerts.The LLWAS is designed to detect low level windshear conditions around the periphery of an airport. Itdoes not detect wind shear beyond that limitation.Controllers will provide this information to pilots bygiving the pilot the airport wind followed by theboundary wind.
EXAMPLE−Wind shear alert, airport wind 230 at 8, south boundarywind 170 at 20.
b. LLWAS “network expansion,” (LLWAS NE)and LLWAS Relocation/Sustainment (LLWAS−RS)are systems integrated with TDWR. These systemsprovide the capability of detecting microburst alertsand wind shear alerts. Controllers will issue theappropriate wind shear alerts or microburst alerts. Insome of these systems controllers also have the abilityto issue wind information oriented to the threshold ordeparture end of the runway.
EXAMPLE−Runway 17 arrival microburst alert, 40 knot loss 3 milefinal.
REFERENCE−AIM, Paragraph 7−1−26 , Microbursts
c. More advanced systems are in the field or beingdeveloped such as ITWS. ITWS provides alerts formicrobursts, wind shear, and significant thunder-storm activity. ITWS displays wind informationoriented to the threshold or departure end of therunway.
d. The WSP provides weather processor enhance-ments to selected Airport Surveillance Radar(ASR)−9 facilities. The WSP provides Air Trafficwith detection and alerting of hazardous weather suchas wind shear, microbursts, and significant thunder-storm activity. The WSP displays terminal area6 level weather, storm cell locations and movement,as well as the location and predicted future position
and intensity of wind shifts that may affect airportoperations. Controllers will receive and issue alertsbased on Areas Noted for Attention (ARENA). AnARENA extends on the runway center line from a3 mile final to the runway to a 2 mile departure.
e. An airport equipped with the LLWAS, ITWS, orWSP is so indicated in the Chart Supplement U.S.under Weather Data Sources for that particularairport.
4−3−8. Braking Action Reports andAdvisories
a. When available, ATC furnishes pilots thequality of braking action received from pilots. Thequality of braking action is described by the terms“good,” “good to medium,” “medium,” “medium topoor,” “poor,” and “nil.” When pilots report thequality of braking action by using the terms notedabove, they should use descriptive terms that areeasily understood, such as, “braking action poor thefirst/last half of the runway,” together with theparticular type of aircraft.
b. FICON NOTAMs will provide contaminantmeasurements for paved runways; however, aFICON NOTAM for braking action will only be usedfor non−paved runway surfaces, taxiways, andaprons. These NOTAMs are classified according tothe most critical term (“good to medium,” “medium,”“medium to poor,” and “poor”).
1. FICON NOTAM reporting of a brakingcondition for paved runway surfaces is notpermissible by Federally Obligated Airports or thoseairports certificated under 14 CFR Part 139.
2. A “NIL” braking condition at these airportsmust be mitigated by closure of the affected surface.Do not include the type of vehicle in the FICONNOTAM.
c. When tower controllers receive runway brakingaction reports which include the terms medium, poor,or nil, or whenever weather conditions are conduciveto deteriorating or rapidly changing runway brakingconditions, the tower will include on the ATISbroadcast the statement, “BRAKING ACTIONADVISORIES ARE IN EFFECT.”
d. During the time that braking action advisoriesare in effect, ATC will issue the most recent brakingaction report for the runway in use to each arrivingand departing aircraft. Pilots should be prepared for
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deteriorating braking conditions and should requestcurrent runway condition information if not issued bycontrollers. Pilots should also be prepared to providea descriptive runway condition report to controllersafter landing.
4−3−9. Runway Condition Reports
a. Aircraft braking coefficient is dependent uponthe surface friction between the tires on the aircraftwheels and the pavement surface. Less friction meansless aircraft braking coefficient and less aircraftbraking response.
b. Runway condition code (RwyCC) values rangefrom 1 (poor) to 6 (dry). For frozen contaminants onrunway surfaces, a runway condition code reading of4 indicates the level when braking deceleration ordirectional control is between good and medium.
NOTE−A RwyCC of “0” is used to delineate a braking actionreport of NIL and is prohibited from being reported in aFICON NOTAM.
c. Airport management should conduct runwaycondition assessments on wet runways or runwayscovered with compacted snow and/or ice.
1. Numerical readings may be obtained by usingthe Runway Condition Assessment Matrix (RCAM).The RCAM provides the airport operator with data tocomplete the report that includes the following:
(a) Runway(s) in use
(b) Time of the assessment
(c) Runway condition codes for each zone(touchdown, mid−point, roll−out)
(e) The contaminant (for example, wet snow,dry snow, slush, ice, etc.)
2. Assessments for each zone (see 4−3−9c1(c))will be issued in the direction of takeoff and landingon the runway, ranging from “1” to “6” to describecontaminated surfaces.
NOTE−A RwyCC of “0” is used to delineate a braking actionreport of NIL and is prohibited from being reported in aFICON NOTAM.
3. When any 1 or more runway condition codesare reported as less than 6, airport management mustnotify ATC for dissemination to pilots.
4. Controllers will not issue runway conditioncodes when all 3 segments of a runway are reportingvalues of 6.
d. When runway condition code reports areprovided by airport management, the ATC facilityproviding approach control or local airport advisorymust provide the report to all pilots.
e. Pilots should use runway condition codeinformation with other knowledge including aircraftperformance characteristics, type, and weight,previous experience, wind conditions, and aircrafttire type (such as bias ply vs. radial constructed) todetermine runway suitability.
f. The Runway Condition Assessment Matrixidentifies the descriptive terms “good,” “good tomedium,” “medium,” “medium to poor,” “poor,” and“nil” used in braking action reports.REFERENCE−Advisory Circular AC 91−79A (Revision 1), Mitigating the Risks of aRunway Overrun Upon Landing, Appendix 1
a. In order to enhance airport capacities, reducetaxiing distances, minimize departure delays, andprovide for more efficient movement of air traffic,controllers may initiate intersection takeoffs as wellas approve them when the pilot requests. If for ANYreason a pilot prefers to use a different intersection orthe full length of the runway or desires to obtain thedistance between the intersection and the runway end,THE PILOT IS EXPECTED TO INFORM ATCACCORDINGLY.
b. Pilots are expected to assess the suitability of anintersection for use at takeoff during their preflightplanning. They must consider the resultant lengthreduction to the published runway length and to thepublished declared distances from the intersectionintended to be used for takeoff. The minimum runwayrequired for takeoff must fall within the reducedrunway length and the reduced declared distancesbefore the intersection can be accepted for takeoff.
REFERENCE−AIM, Paragraph 4−3−6 , Use of Runways/Declared Distances
c. Controllers will issue the measured distancefrom the intersection to the runway end rounded“down” to the nearest 50 feet to any pilot whorequests and to all military aircraft, unless use of theintersection is covered in appropriate directives.Controllers, however, will not be able to inform pilotsof the distance from the intersection to the end of anyof the published declared distances.
REFERENCE−FAA Order JO 7110.65, Paragraph 3−7−1, Ground Traffic Movement
d. An aircraft is expected to taxi to (but not onto)the end of the assigned runway unless prior approvalfor an intersection departure is received from groundcontrol.
e. Pilots should state their position on the airportwhen calling the tower for takeoff from a runwayintersection.
EXAMPLE−Cleveland Tower, Apache Three Seven Two Two Papa, atthe intersection of taxiway Oscar and runway two threeright, ready for departure.
f. Controllers are required to separate smallaircraft that are departing from an intersection on thesame runway (same or opposite direction) behind alarge nonheavy aircraft (except B757), by ensuringthat at least a 3−minute interval exists between the
time the preceding large aircraft has taken off and thesucceeding small aircraft begins takeoff roll. The3−minute separation requirement will also be appliedto small aircraft with a maximum certificated takeoffweight of 12,500 pounds or less departing behind asmall aircraft with a maximum certificated takeoffweight of more than 12,500 pounds. To inform thepilot of the required 3−minute hold, the controller willstate, “Hold for wake turbulence.” If after consider-ing wake turbulence hazards, the pilot feels that alesser time interval is appropriate, the pilot mayrequest a waiver to the 3−minute interval. To initiatesuch a request, simply say “Request waiver to3−minute interval” or a similar statement. Controllersmay then issue a takeoff clearance if other trafficpermits, since the pilot has accepted the responsibilityfor wake turbulence separation.
g. The 3−minute interval is not required when theintersection is 500 feet or less from the departurepoint of the preceding aircraft and both aircraft aretaking off in the same direction. Controllers maypermit the small aircraft to alter course after takeoffto avoid the flight path of the preceding departure.
h. A 4−minute interval is mandatory for small,large, and heavy aircraft behind a super aircraft. The3−minute interval is mandatory behind a heavyaircraft in all cases, and for small aircraft behind aB757.
4−3−11. Pilot Responsibilities WhenConducting Land and Hold ShortOperations (LAHSO)
a. LAHSO is an acronym for “Land and HoldShort Operations.” These operations include landingand holding short of an intersecting runway, anintersecting taxiway, or some other designated pointon a runway other than an intersecting runway ortaxiway. (See FIG 4−3−8, FIG 4−3−9, FIG 4−3−10.)
b. Pilot Responsibilities and Basic Procedures.
1. LAHSO is an air traffic control procedure thatrequires pilot participation to balance the needs forincreased airport capacity and system efficiency,consistent with safety. This procedure can be donesafely provided pilots and controllers are knowledge-able and understand their responsibilities. Thefollowing paragraphs outline specific pilot/operatorresponsibilities when conducting LAHSO.
2. At controlled airports, air traffic may clear apilot to land and hold short. Pilots may accept such a
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clearance provided that the pilot−in−commanddetermines that the aircraft can safely land and stopwithin the Available Landing Distance (ALD). ALDdata are published in the special notices section of theChart Supplement U.S. and in the U.S. TerminalProcedures Publications. Controllers will alsoprovide ALD data upon request. Student pilots orpilots not familiar with LAHSO should notparticipate in the program.
3. The pilot−in−command has the final authori-ty to accept or decline any land and hold shortclearance. The safety and operation of the aircraftremain the responsibility of the pilot. Pilots areexpected to decline a LAHSO clearance if theydetermine it will compromise safety.
4. To conduct LAHSO, pilots should becomefamiliar with all available information concerningLAHSO at their destination airport. Pilots shouldhave, readily available, the published ALD andrunway slope information for all LAHSO runwaycombinations at each airport of intended landing.Additionally, knowledge about landing performancedata permits the pilot to readily determine that theALD for the assigned runway is sufficient for safeLAHSO. As part of a pilot’s preflight planningprocess, pilots should determine if their destinationairport has LAHSO. If so, their preflight planningprocess should include an assessment of whichLAHSO combinations would work for them giventheir aircraft’s required landing distance. Good pilotdecision making is knowing in advance whether onecan accept a LAHSO clearance if offered.
FIG 4−3−8Land and Hold Short of an Intersecting Runway
EXAMPLE−FIG 4−3−10 − holding short at a designated point may berequired to avoid conflicts with the runway safetyarea/flight path of a nearby runway.NOTE−Each figure shows the approximate location of LAHSOmarkings, signage, and in−pavement lighting wheninstalled.REFERENCE−AIM, Chapter 2, Aeronautical Lighting and Other Airport Visual Aids.
FIG 4−3−9Land and Hold Short of an Intersecting Taxiway
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FIG 4−3−10Land and Hold Short of a Designated Pointon a Runway Other Than an Intersecting
Runway or Taxiway
5. If, for any reason, such as difficulty indiscerning the location of a LAHSO intersection,wind conditions, aircraft condition, etc., the pilotelects to request to land on the full length of therunway, to land on another runway, or to declineLAHSO, a pilot is expected to promptly inform airtraffic, ideally even before the clearance is issued. ALAHSO clearance, once accepted, must be adheredto, just as any other ATC clearance, unless anamended clearance is obtained or an emergencyoccurs. A LAHSO clearance does not preclude arejected landing.
6. A pilot who accepts a LAHSO clearanceshould land and exit the runway at the first convenienttaxiway (unless directed otherwise) before reachingthe hold short point. Otherwise, the pilot must stopand hold at the hold short point. If a rejected landingbecomes necessary after accepting a LAHSOclearance, the pilot should maintain safe separationfrom other aircraft or vehicles, and should promptlynotify the controller.
7. Controllers need a full read back of allLAHSO clearances. Pilots should read back theirLAHSO clearance and include the words, “HOLDSHORT OF (RUNWAY/TAXIWAY/OR POINT)” intheir acknowledgment of all LAHSO clearances. Inorder to reduce frequency congestion, pilots areencouraged to read back the LAHSO clearance
without prompting. Don’t make the controller have toask for a read back!
c. LAHSO Situational Awareness
1. Situational awareness is vital to the success ofLAHSO. Situational awareness starts with havingcurrent airport information in the cockpit, readilyaccessible to the pilot. (An airport diagram assistspilots in identifying their location on the airport, thusreducing requests for “progressive taxi instructions”from controllers.)
2. Situational awareness includes effectivepilot−controller radio communication. ATC expectspilots to specifically acknowledge and read back allLAHSO clearances as follows:
EXAMPLE−ATC: “(Aircraft ID) cleared to land runway six right, holdshort of taxiway bravo for crossing traffic (type aircraft).”Aircraft: “(Aircraft ID), wilco, cleared to land runway sixright to hold short of taxiway bravo.”ATC: “(Aircraft ID) cross runway six right at taxiwaybravo, landing aircraft will hold short.”Aircraft: “(Aircraft ID), wilco, cross runway six right atbravo, landing traffic (type aircraft) to hold.”
3. For those airplanes flown with two crew-members, effective intra−cockpit communicationbetween cockpit crewmembers is also critical. Therehave been several instances where the pilot workingthe radios accepted a LAHSO clearance but thensimply forgot to tell the pilot flying the aircraft.
4. Situational awareness also includes a thor-ough understanding of the airport markings, signage,and lighting associated with LAHSO. These visualaids consist of a three−part system of yellowhold−short markings, red and white signage and, incertain cases, in−pavement lighting. Visual aids assistthe pilot in determining where to hold short.FIG 4−3−8, FIG 4−3−9, FIG 4−3−10 depict howthese markings, signage, and lighting combinationswill appear once installed. Pilots are cautioned thatnot all airports conducting LAHSO have installed anyor all of the above markings, signage, or lighting.
5. Pilots should only receive a LAHSOclearance when there is a minimum ceiling of1,000 feet and 3 statute miles visibility. The intent ofhaving “basic” VFR weather conditions is to allowpilots to maintain visual contact with other aircraftand ground vehicle operations. Pilots should considerthe effects of prevailing inflight visibility (such aslanding into the sun) and how it may affect overall
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situational awareness. Additionally, surface vehiclesand aircraft being taxied by maintenance personnelmay also be participating in LAHSO, especially inthose operations that involve crossing an activerunway.
4−3−12. Low Approach
a. A low approach (sometimes referred to as a lowpass) is the go−around maneuver following anapproach. Instead of landing or making a touch−and−go, a pilot may wish to go around (low approach) inorder to expedite a particular operation (a series ofpractice instrument approaches is an example of suchan operation). Unless otherwise authorized by ATC,the low approach should be made straight ahead, withno turns or climb made until the pilot has made athorough visual check for other aircraft in the area.
b. When operating within a Class B, Class C, andClass D surface area, a pilot intending to make a lowapproach should contact the tower for approval. Thisrequest should be made prior to starting the finalapproach.
c. When operating to an airport, not within aClass B, Class C, and Class D surface area, a pilotintending to make a low approach should, prior toleaving the final approach fix inbound (nonprecisionapproach) or the outer marker or fix used in lieu of theouter marker inbound (precision approach), so advisethe FSS, UNICOM, or make a broadcast asappropriate.REFERENCE−AIM, Paragraph 4−1−9 , Traffic Advisory Practices at Airports WithoutOperating Control Towers
4−3−13. Traffic Control Light Signals
a. The following procedures are used by ATCTs inthe control of aircraft, ground vehicles, equipment,
and personnel not equipped with radio. These sameprocedures will be used to control aircraft, groundvehicles, equipment, and personnel equipped withradio if radio contact cannot be established. ATCpersonnel use a directive traffic control signal whichemits an intense narrow light beam of a selected color(either red, white, or green) when controlling trafficby light signals.
b. Although the traffic signal light offers theadvantage that some control may be exercised overnonradio equipped aircraft, pilots should be cog-nizant of the disadvantages which are:
1. Pilots may not be looking at the control towerat the time a signal is directed toward their aircraft.
2. The directions transmitted by a light signalare very limited since only approval or disapproval ofa pilot’s anticipated actions may be transmitted. Nosupplement or explanatory information may betransmitted except by the use of the “GeneralWarning Signal” which advises the pilot to be on thealert.
c. Between sunset and sunrise, a pilot wishing toattract the attention of the control tower should turnon a landing light and taxi the aircraft into a position,clear of the active runway, so that light is visible to thetower. The landing light should remain on untilappropriate signals are received from the tower.
d. Airport Traffic Control Tower Light GunSignals. (See TBL 4−3−1.)
e. During daylight hours, acknowledge towertransmissions or light signals by moving the aileronsor rudder. At night, acknowledge by blinking thelanding or navigation lights. If radio malfunctionoccurs after departing the parking area, watch thetower for light signals or monitor tower frequency.
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TBL 4−3−1Airport Traffic Control Tower Light Gun Signals
Meaning
Color and Type of SignalMovement of Vehicles,
Equipment and Personnel Aircraft on the Ground Aircraft in Flight
Steady green Cleared to cross, proceed or go Cleared for takeoff Cleared to land
Flashing green Not applicable Cleared for taxi Return for landing (to befollowed by steady green at theproper time)
Steady red STOP STOP Give way to other aircraft andcontinue circling
Flashing red Clear the taxiway/runway Taxi clear of the runway in use Airport unsafe, do not land
Flashing white Return to starting point on airport Return to starting point on airport Not applicable
Alternating red and green Exercise extreme caution Exercise extreme caution Exercise extreme caution
4−3−14. Communications
a. Pilots of departing aircraft should communicatewith the control tower on the appropriate groundcontrol/clearance delivery frequency prior to startingengines to receive engine start time, taxi and/orclearance information. Unless otherwise advised bythe tower, remain on that frequency during taxiingand runup, then change to local control frequencywhen ready to request takeoff clearance.
NOTE−Pilots are encouraged to monitor the local tower frequencyas soon as practical consistent with other ATCrequirements.REFERENCE−AIM, Paragraph 4−1−13 , Automatic Terminal Information Service(ATIS)
b. The tower controller will consider that pilots ofturbine−powered aircraft are ready for takeoff whenthey reach the runway or warm−up block unlessadvised otherwise.
c. The majority of ground control frequencies arein the 121.6−121.9 MHz bandwidth. Ground controlfrequencies are provided to eliminate frequencycongestion on the tower (local control) frequency andare limited to communications between the tower andaircraft on the ground and between the tower andutility vehicles on the airport, provide a clear VHFchannel for arriving and departing aircraft. They areused for issuance of taxi information, clearances, andother necessary contacts between the tower andaircraft or other vehicles operated on the airport. Apilot who has just landed should not change from the
tower frequency to the ground control frequency untildirected to do so by the controller. Normally, only oneground control frequency is assigned at an airport;however, at locations where the amount of traffic sowarrants, a second ground control frequency and/oranother frequency designated as a clearance deliveryfrequency, may be assigned.
d. A controller may omit the ground or localcontrol frequency if the controller believes the pilotknows which frequency is in use. If the groundcontrol frequency is in the 121 MHz bandwidth thecontroller may omit the numbers preceding thedecimal point; e.g., 121.7, “CONTACT GROUNDPOINT SEVEN.” However, if any doubt exists as towhat frequency is in use, the pilot should promptlyrequest the controller to provide that information.
e. Controllers will normally avoid issuing a radiofrequency change to helicopters, known to besingle−piloted, which are hovering, air taxiing, orflying near the ground. At times, it may be necessaryfor pilots to alert ATC regarding single pilotoperations to minimize delay of essential ATCcommunications. Whenever possible, ATC instruc-tions will be relayed through the frequency beingmonitored until a frequency change can beaccomplished. You must promptly advise ATC if youare unable to comply with a frequency change. Also,you should advise ATC if you must land toaccomplish the frequency change unless it is clear thelanding will have no impact on other air traffic;e.g., on a taxiway or in a helicopter operating area.
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4−3−15. Gate Holding Due to DepartureDelays
a. Pilots should contact ground control orclearance delivery prior to starting engines as gatehold procedures will be in effect whenever departuredelays exceed or are anticipated to exceed15 minutes. The sequence for departure will bemaintained in accordance with initial call up unlessmodified by flow control restrictions. Pilots shouldmonitor the ground control or clearance deliveryfrequency for engine startup advisories or newproposed start time if the delay changes.
b. The tower controller will consider that pilots ofturbine−powered aircraft are ready for takeoff whenthey reach the runway or warm−up block unlessadvised otherwise.
4−3−16. VFR Flights in Terminal Areas
Use reasonable restraint in exercising the prerogativeof VFR flight, especially in terminal areas. Theweather minimums and distances from clouds areminimums. Giving yourself a greater margin inspecific instances is just good judgment.
a. Approach Area. Conducting a VFR operationin a Class B, Class C, Class D, and Class E surfacearea when the official visibility is 3 or 4 miles is notprohibited, but good judgment would dictate that youkeep out of the approach area.
b. Reduced Visibility. It has always been recog-nized that precipitation reduces forward visibility.Consequently, although again it may be perfectlylegal to cancel your IFR flight plan at any time youcan proceed VFR, it is good practice, whenprecipitation is occurring, to continue IFR operationinto a terminal area until you are reasonably close toyour destination.
c. Simulated Instrument Flights. In conductingsimulated instrument flights, be sure that the weatheris good enough to compensate for the restrictedvisibility of the safety pilot and your greaterconcentration on your flight instruments. Giveyourself a little greater margin when your flight planlies in or near a busy airway or close to an airport.
1. The following ATC procedures and phrase-ologies recognize the unique capabilities ofhelicopters and were developed to improve service toall users. Helicopter design characteristics and userneeds often require operations from movement areasand nonmovement areas within the airport boundary.In order for ATC to properly apply these procedures,it is essential that pilots familiarize themselves withthe local operations and make it known to controllerswhen additional instructions are necessary.
2. Insofar as possible, helicopter operations willbe instructed to avoid the flow of fixed−wing aircraftto minimize overall delays; however, there will bemany situations where faster/larger helicopters maybe integrated with fixed−wing aircraft for the benefitof all concerned. Examples would include IFRflights, avoidance of noise sensitive areas, or use ofrunways/taxiways to minimize the hazardous effectsof rotor downwash in congested areas.
3. Because helicopter pilots are intimatelyfamiliar with the effects of rotor downwash, they arebest qualified to determine if a given operation can beconducted safely. Accordingly, the pilot has the finalauthority with respect to the specific airspeed/altitudecombinations. ATC clearances are in no way intendedto place the helicopter in a hazardous position. It isexpected that pilots will advise ATC if a specificclearance will cause undue hazards to persons orproperty.
b. Controllers normally limit ATC ground serviceand instruction to movement areas; therefore,operations from nonmovement areas are conducted atpilot discretion and should be based on local policies,procedures, or letters of agreement. In order tomaximize the flexibility of helicopter operations, it isnecessary to rely heavily on sound pilot judgment.For example, hazards such as debris, obstructions,vehicles, or personnel must be recognized by thepilot, and action should be taken as necessary to avoidsuch hazards. Taxi, hover taxi, and air taxi operationsare considered to be ground movements. Helicoptersconducting such operations are expected to adhere tothe same conditions, requirements, and practices asapply to other ground taxiing and ATC procedures inthe AIM.
1. The phraseology taxi is used when it isintended or expected that the helicopter will taxi onthe airport surface, either via taxiways or otherprescribed routes. Taxi is used primarily forhelicopters equipped with wheels or in response to a
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pilot request. Preference should be given to thisprocedure whenever it is necessary to minimizeeffects of rotor downwash.
2. Pilots may request a hover taxi when slowforward movement is desired or when it may beappropriate to move very short distances. Pilotsshould avoid this procedure if rotor downwash islikely to cause damage to parked aircraft or if blowingdust/snow could obscure visibility. If it is necessaryto operate above 25 feet AGL when hover taxiing, thepilot should initiate a request to ATC.
3. Air taxi is the preferred method for helicopterground movements on airports provided groundoperations and conditions permit. Unless otherwiserequested or instructed, pilots are expected to remainbelow 100 feet AGL. However, if a higher thannormal airspeed or altitude is desired, the requestshould be made prior to lift−off. The pilot is solelyresponsible for selecting a safe airspeed for thealtitude/operation being conducted. Use of air taxienables the pilot to proceed at an optimumairspeed/altitude, minimize downwash effect, con-serve fuel, and expedite movement from one point toanother. Helicopters should avoid overflight of otheraircraft, vehicles, and personnel during air−taxioperations. Caution must be exercised concerningactive runways and pilots must be certain that air taxiinstructions are understood. Special precautions maybe necessary at unfamiliar airports or airports withmultiple/intersecting active runways. The taxiprocedures given in Paragraph 4−3−18, Taxiing,Paragraph 4−3−19, Taxi During Low Visibility, andParagraph 4−3−20, Exiting the Runway AfterLanding, also apply.REFERENCE−Pilot/Controller Glossary Term− Taxi.Pilot/Controller Glossary Term− Hover Taxi.Pilot/Controller Glossary Term− Air Taxi.
c. Takeoff and Landing Procedures.
1. Helicopter operations may be conductedfrom a runway, taxiway, portion of a landing strip, orany clear area which could be used as a landing sitesuch as the scene of an accident, a construction site,or the roof of a building. The terms used to describedesignated areas from which helicopters operate are:movement area, landing/takeoff area, apron/ramp,heliport and helipad (See Pilot/Controller Glossary).
These areas may be improved or unimproved andmay be separate from or located on an airport/heli-port. ATC will issue takeoff clearances frommovement areas other than active runways, or indiverse directions from active runways, withadditional instructions as necessary. Wheneverpossible, takeoff clearance will be issued in lieu ofextended hover/air taxi operations. Phraseology willbe “CLEARED FOR TAKEOFF FROM (taxiway,helipad, runway number, etc.), MAKE RIGHT/LEFT TURN FOR (direction, heading, NAVAIDradial) DEPARTURE/DEPARTURE ROUTE (num-ber, name, etc.).” Unless requested by the pilot,downwind takeoffs will not be issued if the tailwindexceeds 5 knots.
2. Pilots should be alert to wind information aswell as to wind indications in the vicinity of thehelicopter. ATC should be advised of the intendedmethod of departing. A pilot request to takeoff in agiven direction indicates that the pilot is willing toaccept the wind condition and controllers will honorthe request if traffic permits. Departure points couldbe a significant distance from the control tower andit may be difficult or impossible for the controller todetermine the helicopter’s relative position to thewind.
3. If takeoff is requested from nonmovementareas, an area not authorized for helicopter use, anarea not visible from the tower, an unlighted area atnight, or an area off the airport, the phraseology“DEPARTURE FROM (requested location) WILLBE AT YOUR OWN RISK (additional instructions,as necessary). USE CAUTION (if applicable).” Thepilot is responsible for operating in a safe manner andshould exercise due caution.
4. Similar phraseology is used for helicopterlanding operations. Every effort will be made topermit helicopters to proceed direct and land as nearas possible to their final destination on the airport.Traffic density, the need for detailed taxiinginstructions, frequency congestion, or other factorsmay affect the extent to which service can beexpedited. As with ground movement operations, ahigh degree of pilot/controller cooperation andcommunication is necessary to achieve safe andefficient operations.
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4−3−18. Taxiing
a. General. Approval must be obtained prior tomoving an aircraft or vehicle onto the movement areaduring the hours an Airport Traffic Control Tower isin operation.
1. Always state your position on the airportwhen calling the tower for taxi instructions.
2. The movement area is normally described inlocal bulletins issued by the airport manager orcontrol tower. These bulletins may be found in FSSs,fixed base operators offices, air carrier offices, andoperations offices.
3. The control tower also issues bulletinsdescribing areas where they cannot provide ATCservice due to nonvisibility or other reasons.
4. A clearance must be obtained prior to taxiingon a runway, taking off, or landing during the hoursan Airport Traffic Control Tower is in operation.
5. A clearance must be obtained prior tocrossing any runway. ATC will issue an explicitclearance for all runway crossings.
6. When assigned a takeoff runway, ATC willfirst specify the runway, issue taxi instructions, andstate any hold short instructions or runway crossingclearances if the taxi route will cross a runway. Thisdoes not authorize the aircraft to “enter” or “cross”the assigned departure runway at any point. In orderto preclude misunderstandings in radio communica-tions, ATC will not use the word “cleared” inconjunction with authorization for aircraft to taxi.
7. When issuing taxi instructions to any pointother than an assigned takeoff runway, ATC willspecify the point to taxi to, issue taxi instructions, andstate any hold short instructions or runway crossingclearances if the taxi route will cross a runway.
NOTE−ATC is required to obtain a readback from the pilot of allrunway hold short instructions.
8. If a pilot is expected to hold short of arunway approach/departure (Runway XX APPCH/Runway XX DEP) hold area or ILS holding position(see FIG 2−3−15, Taxiways Located in RunwayApproach Area), ATC will issue instructions.
9. When taxi instructions are received from thecontroller, pilots should always read back:
(a) The runway assignment.
(b) Any clearance to enter a specific runway.
(c) Any instruction to hold short of a specificrunway or line up and wait.
Controllers are required to request a readback ofrunway hold short assignment when it is not receivedfrom the pilot/vehicle.
b. ATC clearances or instructions pertaining totaxiing are predicated on known traffic and knownphysical airport conditions. Therefore, it is importantthat pilots clearly understand the clearance orinstruction. Although an ATC clearance is issued fortaxiing purposes, when operating in accordance withthe CFRs, it is the responsibility of the pilot to avoidcollision with other aircraft. Since “the pilot−in−com-mand of an aircraft is directly responsible for, and isthe final authority as to, the operation of that aircraft”the pilot should obtain clarification of any clearanceor instruction which is not understood.REFERENCE−AIM, Paragraph 7−3−1 , General
1. Good operating practice dictates that pilotsacknowledge all runway crossing, hold short, ortakeoff clearances unless there is some misunder-standing, at which time the pilot should query thecontroller until the clearance is understood.
NOTE−Air traffic controllers are required to obtain from the pilota readback of all runway hold short instructions.
2. Pilots operating a single pilot aircraft shouldmonitor only assigned ATC communications afterbeing cleared onto the active runway for departure.Single pilot aircraft should not monitor other thanATC communications until flight from Class B,Class C, or Class D surface area is completed. Thissame procedure should be practiced from after receiptof the clearance for landing until the landing and taxiactivities are complete. Proper effective scanning forother aircraft, surface vehicles, or other objectsshould be continuously exercised in all cases.
3. If the pilot is unfamiliar with the airport or forany reason confusion exists as to the correct taxirouting, a request may be made for progressive taxiinstructions which include step−by−step routingdirections. Progressive instructions may also beissued if the controller deems it necessary due totraffic or field conditions (for example, constructionor closed taxiways).
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c. At those airports where the U.S. Governmentoperates the control tower and ATC has authorizednoncompliance with the requirement for two−wayradio communications while operating within theClass B, Class C, or Class D surface area, or at thoseairports where the U.S. Government does not operatethe control tower and radio communications cannotbe established, pilots must obtain a clearance byvisual light signal prior to taxiing on a runway andprior to takeoff and landing.
d. The following phraseologies and proceduresare used in radiotelephone communications withaeronautical ground stations.
1. Request for taxi instructions prior todeparture. State your aircraft identification, loca-tion, type of operation planned (VFR or IFR), and thepoint of first intended landing.
EXAMPLE−Aircraft: “Washington ground, Beechcraft One Three OneFive Niner at hangar eight, ready to taxi, I−F−R toChicago.” Tower: “Beechcraft one three one five niner, Washingtonground, runway two seven, taxi via taxiways Charlie andDelta, hold short of runway three three left.”
Aircraft: “Beechcraft One Three One Five Niner, holdshort of runway three three left.”
2. Receipt of ATC clearance. ARTCC clear-ances are relayed to pilots by airport trafficcontrollers in the following manner.
EXAMPLE−Tower: “Beechcraft One Three One Five Niner, cleared tothe Chicago Midway Airport via Victor Eight, maintaineight thousand.”
Aircraft: “Beechcraft One Three One Five Niner, clearedto the Chicago Midway Airport via Victor Eight, maintaineight thousand.”
NOTE−Normally, an ATC IFR clearance is relayed to a pilot by theground controller. At busy locations, however, pilots maybe instructed by the ground controller to “contactclearance delivery” on a frequency designated for thispurpose. No surveillance or control over the movement oftraffic is exercised by this position of operation.
3. Request for taxi instructions after landing.State your aircraft identification, location, and thatyou request taxi instructions.
EXAMPLE−Aircraft: “Dulles ground, Beechcraft One Four Two SixOne clearing runway one right on taxiway echo three,request clearance to Page.”
Tower: “Beechcraft One Four Two Six One, Dullesground, taxi to Page via taxiways echo three, echo one, andecho niner.”
or
Aircraft: “Orlando ground, Beechcraft One Four Two SixOne clearing runway one eight left at taxiway bravo three,request clearance to Page.”
Tower: “Beechcraft One Four Two Six One, Orlandoground, hold short of runway one eight right.”
Aircraft: “Beechcraft One Four Two Six One, hold shortof runway one eight right.”
4−3−19. Taxi During Low Visibility
a. Pilots and aircraft operators should be constant-ly aware that during certain low visibility conditionsthe movement of aircraft and vehicles on airports maynot be visible to the tower controller. This mayprevent visual confirmation of an aircraft’s adherenceto taxi instructions.
b. Of vital importance is the need for pilots tonotify the controller when difficulties are encoun-tered or at the first indication of becomingdisoriented. Pilots should proceed with extremecaution when taxiing toward the sun. When visiondifficulties are encountered pilots should immediate-ly inform the controller.
c. Advisory Circular 120−57, Low VisibilityOperations Surface Movement Guidance and ControlSystem, commonly known as LVOSMGCS (pro-nounced “LVO SMIGS”) describes an adequateexample of a low visibility taxi plan for any airportwhich has takeoff or landing operations in less than1,200 feet runway visual range (RVR) visibilityconditions. These plans, which affect aircrew andvehicle operators, may incorporate additionallighting, markings, and procedures to control airportsurface traffic. They will be addressed at two levels;operations less than 1,200 feet RVR to 500 feet RVRand operations less than 500 feet RVR.NOTE−Specific lighting systems and surface markings may befound in Paragraph 2−1−11, Taxiway Lights, andParagraph 2−3−4 , Taxiway Markings.
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d. When low visibility conditions exist, pilotsshould focus their entire attention on the safeoperation of the aircraft while it is moving. Checklistsand nonessential communication should be withhelduntil the aircraft is stopped and the brakes set.
4−3−20. Exiting the Runway After Landing
The following procedures must be followed afterlanding and reaching taxi speed.
a. Exit the runway without delay at the firstavailable taxiway or on a taxiway as instructed byATC. Pilots must not exit the landing runway ontoanother runway unless authorized by ATC. Atairports with an operating control tower, pilots shouldnot stop or reverse course on the runway without firstobtaining ATC approval.
b. Taxi clear of the runway unless otherwisedirected by ATC. An aircraft is considered clear of therunway when all parts of the aircraft are past therunway edge and there are no restrictions to itscontinued movement beyond the runway holdingposition markings. In the absence of ATC instruc-tions, the pilot is expected to taxi clear of the landingrunway by taxiing beyond the runway holdingposition markings associated with the landingrunway, even if that requires the aircraft to protrudeinto or cross another taxiway or ramp area. Once allparts of the aircraft have crossed the runway holdingposition markings, the pilot must hold unless furtherinstructions have been issued by ATC.
NOTE−1. The tower will issue the pilot instructions which willpermit the aircraft to enter another taxiway, runway, orramp area when required.
2. Guidance contained in subparagraphs a and b above isconsidered an integral part of the landing clearance andsatisfies the requirement of 14 CFR Section 91.129.
c. Immediately change to ground control frequen-cy when advised by the tower and obtain a taxiclearance.
NOTE−1. The tower will issue instructions required to resolve anypotential conflictions with other ground traffic prior toadvising the pilot to contact ground control.
2. Ground control will issue taxi clearance to parking.That clearance does not authorize the aircraft to “enter”or “cross” any runways. Pilots not familiar with the taxiroute should request specific taxi instructions from ATC.
4−3−21. Practice Instrument Approaches
a. Various air traffic incidents have indicated thenecessity for adoption of measures to achieve moreorganized and controlled operations where practiceinstrument approaches are conducted. Practiceinstrument approaches are considered to be instru-ment approaches made by either a VFR aircraft not onan IFR flight plan or an aircraft on an IFR flight plan.To achieve this and thereby enhance air safety, it isAir Traffic’s policy to provide for separation of suchoperations at locations where approach controlfacilities are located and, as resources permit, atcertain other locations served by ARTCCs or parentapproach control facilities. Pilot requests to practiceinstrument approaches may be approved by ATCsubject to traffic and workload conditions. Pilotsshould anticipate that in some instances the controllermay find it necessary to deny approval or withdrawprevious approval when traffic conditions warrant. Itmust be clearly understood, however, that eventhough the controller may be providing separation,pilots on VFR flight plans are required to comply withbasic VFR weather minimums (14 CFR Sec-tion 91.155). Application of ATC procedures or anyaction taken by the controller to avoid trafficconflictions does not relieve IFR and VFR pilots oftheir responsibility to see−and−avoid other trafficwhile operating in VFR conditions (14 CFRSection 91.113). In addition to the normal IFRseparation minimums (which includes visual separa-tion) during VFR conditions, 500 feet verticalseparation may be applied between VFR aircraft andbetween a VFR aircraft and the IFR aircraft. Pilots noton IFR flight plans desiring practice instrumentapproaches should always state ‘practice’ whenmaking requests to ATC. Controllers will instructVFR aircraft requesting an instrument approach tomaintain VFR. This is to preclude misunderstandingsbetween the pilot and controller as to the status of theaircraft. If pilots wish to proceed in accordance withinstrument flight rules, they must specifically requestand obtain, an IFR clearance.
b. Before practicing an instrument approach,pilots should inform the approach control facility orthe tower of the type of practice approach they desireto make and how they intend to terminate it,i.e., full−stop landing, touch−and−go, or missed orlow approach maneuver. This information may befurnished progressively when conducting a series ofapproaches. Pilots on an IFR flight plan, who have
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made a series of instrument approaches to full stoplandings should inform ATC when they make theirfinal landing. The controller will control flightspracticing instrument approaches so as to ensure thatthey do not disrupt the flow of arriving and departingitinerant IFR or VFR aircraft. The priority affordeditinerant aircraft over practice instrument approachesis not intended to be so rigidly applied that it causesgrossly inefficient application of services. Aminimum delay to itinerant traffic may be appropriateto allow an aircraft practicing an approach tocomplete that approach.
NOTE−A clearance to land means that appropriate separation onthe landing runway will be ensured. A landing clearancedoes not relieve the pilot from compliance with anypreviously issued restriction.
c. At airports without a tower, pilots wishing tomake practice instrument approaches should notifythe facility having control jurisdiction of the desiredapproach as indicated on the approach chart. Allapproach control facilities and ARTCCs are requiredto publish a Letter to Airmen depicting those airportswhere they provide standard separation to both VFRand IFR aircraft conducting practice instrumentapproaches.
d. The controller will provide approved separationbetween both VFR and IFR aircraft when authoriza-tion is granted to make practice approaches to airportswhere an approach control facility is located and tocertain other airports served by approach control oran ARTCC. Controller responsibility for separationof VFR aircraft begins at the point where theapproach clearance becomes effective, or when theaircraft enters Class B or Class C airspace, or a TRSA,whichever comes first.
e. VFR aircraft practicing instrument approachesare not automatically authorized to execute themissed approach procedure. This authorization mustbe specifically requested by the pilot and approved bythe controller. Separation will not be provided unlessthe missed approach has been approved by ATC.
f. Except in an emergency, aircraft cleared topractice instrument approaches must not deviate fromthe approved procedure until cleared to do so by thecontroller.
g. At radar approach control locations when a fullapproach procedure (procedure turn, etc.,) cannot be
approved, pilots should expect to be vectored to afinal approach course for a practice instrumentapproach which is compatible with the generaldirection of traffic at that airport.
h. When granting approval for a practiceinstrument approach, the controller will usually askthe pilot to report to the tower prior to or over the finalapproach fix inbound (nonprecision approaches) orover the outer marker or fix used in lieu of the outermarker inbound (precision approaches).
i. When authorization is granted to conductpractice instrument approaches to an airport with atower, but where approved standard separation is notprovided to aircraft conducting practice instrumentapproaches, the tower will approve the practiceapproach, instruct the aircraft to maintain VFR andissue traffic information, as required.
j. When an aircraft notifies a FSS providing LocalAirport Advisory to the airport concerned of theintent to conduct a practice instrument approach andwhether or not separation is to be provided, the pilotwill be instructed to contact the appropriate facilityon a specified frequency prior to initiating theapproach. At airports where separation is notprovided, the FSS will acknowledge the message andissue known traffic information but will neitherapprove or disapprove the approach.
k. Pilots conducting practice instrument ap-proaches should be particularly alert for other aircraftoperating in the local traffic pattern or in proximity tothe airport.
4−3−22. Option Approach
The “Cleared for the Option” procedure will permitan instructor, flight examiner or pilot the option tomake a touch−and−go, low approach, missedapproach, stop−and−go, or full stop landing. Thisprocedure can be very beneficial in a trainingsituation in that neither the student pilot nor examineewould know what maneuver would be accomplished.The pilot should make a request for this procedurepassing the final approach fix inbound on aninstrument approach or entering downwind for a VFRtraffic pattern. After ATC approval of the option, thepilot should inform ATC as soon as possible of anydelay on the runway during their stop-and-go or fullstop landing. The advantages of this procedure as atraining aid are that it enables an instructor orexaminer to obtain the reaction of a trainee or
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examinee under changing conditions, the pilot wouldnot have to discontinue an approach in the middle ofthe procedure due to student error or pilot proficiencyrequirements, and finally it allows more flexibilityand economy in training programs. This procedurewill only be used at those locations with anoperational control tower and will be subject to ATCapproval.
4−3−23. Use of Aircraft Lights
a. Aircraft position lights are required to be lightedon aircraft operated on the surface and in flight fromsunset to sunrise. In addition, aircraft equipped withan anti−collision light system are required to operatethat light system during all types of operations (dayand night). However, during any adverse meteorolog-ical conditions, the pilot−in−command maydetermine that the anti−collision lights should beturned off when their light output would constitute ahazard to safety (14 CFR Section 91.209).Supplementary strobe lights should be turned off onthe ground when they adversely affect groundpersonnel or other pilots, and in flight when there areadverse reflection from clouds.
b. An aircraft anti−collision light system can useone or more rotating beacons and/or strobe lights, becolored either red or white, and have different (higherthan minimum) intensities when compared to otheraircraft. Many aircraft have both a rotating beaconand a strobe light system.
c. The FAA has a voluntary pilot safety program,Operation Lights On, to enhance the see−and−avoidconcept. Pilots are encouraged to turn on their landinglights during takeoff; i.e., either after takeoffclearance has been received or when beginningtakeoff roll. Pilots are further encouraged to turn ontheir landing lights when operating below10,000 feet, day or night, especially when operatingwithin 10 miles of any airport, or in conditions ofreduced visibility and in areas where flocks of birdsmay be expected, i.e., coastal areas, lake areas,around refuse dumps, etc. Although turning onaircraft lights does enhance the see−and−avoidconcept, pilots should not become complacent aboutkeeping a sharp lookout for other aircraft. Not allaircraft are equipped with lights and some pilots maynot have their lights turned on. Aircraft manufactur-
er’s recommendations for operation of landing lightsand electrical systems should be observed.
d. Prop and jet blast forces generated by largeaircraft have overturned or damaged several smalleraircraft taxiing behind them. To avoid similar results,and in the interest of preventing upsets and injuries toground personnel from such forces, the FAArecommends that air carriers and commercialoperators turn on their rotating beacons anytime theiraircraft engines are in operation. General aviationpilots using rotating beacon equipped aircraft are alsoencouraged to participate in this program which isdesigned to alert others to the potential hazard. Sincethis is a voluntary program, exercise caution and donot rely solely on the rotating beacon as an indicationthat aircraft engines are in operation.
e. Prior to commencing taxi, it is recommended toturn on navigation, position, anti-collision, and logolights (if equipped). To signal intent to other pilots,consider turning on the taxi light when the aircraft ismoving or intending to move on the ground, andturning it off when stopped or yielding to otherground traffic. Strobe lights should not be illuminatedduring taxi if they will adversely affect the vision ofother pilots or ground personnel.
f. At the discretion of the pilot-in-command, allexterior lights should be illuminated when taxiing onor across any runway. This increases the conspicu-ousness of the aircraft to controllers and other pilotsapproaching to land, taxiing, or crossing the runway.Pilots should comply with any equipment operatinglimitations and consider the effects of landing andstrobe lights on other aircraft in their vicinity.
g. When entering the departure runway for takeoffor to “line up and wait,” all lights, except for landinglights, should be illuminated to make the aircraftconspicuous to ATC and other aircraft on approach.Landing lights should be turned on when takeoffclearance is received or when commencing takeoffroll at an airport without an operating control tower.
4−3−24. Flight Inspection/‘Flight Check’Aircraft in Terminal Areas
a. Flight check is a call sign used to alert pilots andair traffic controllers when a FAA aircraft is engagedin flight inspection/certification of NAVAIDs andflight procedures. Flight check aircraft fly preplannedhigh/low altitude flight patterns such as grids, orbits,
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DME arcs, and tracks, including low passes along thefull length of the runway to verify NAVAIDperformance.
b. Pilots should be especially watchful and avoidthe flight paths of any aircraft using the call sign“Flight Check.” These flights will normally receivespecial handling from ATC. Pilot patience andcooperation in allowing uninterrupted recordings cansignificantly help expedite flight inspections, mini-mize costly, repetitive runs, and reduce the burden onthe U.S. taxpayer.
4−3−25. Hand Signals
FIG 4−3−11Signalman Directs Towing
SIGNALMANSIGNALMAN
FIG 4−3−12Signalman’s Position
SIGNALMANSIGNALMAN
FIG 4−3−13All Clear
(O.K.)
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FIG 4−3−14Start Engine
POINTTOENGINETO BESTARTED
FIG 4−3−15Pull Chocks
FIG 4−3−16Proceed Straight Ahead
FIG 4−3−17Left Turn
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FIG 4−3−18Right Turn
FIG 4−3−19Slow Down
FIG 4−3−20Flagman Directs Pilot
FIG 4−3−21Insert Chocks
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FIG 4−3−22Cut Engines
FIG 4−3−23Night Operation
Use same hand movementsas day operation
FIG 4−3−24Stop
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4−3−32 Airport Operations
4−3−26. Operations at UncontrolledAirports With Automated SurfaceObserving System (ASOS)/AutomatedWeather Sensor System(AWSS)/AutomatedWeather Observing System (AWOS)
a. Many airports throughout the NationalAirspace System are equipped with either ASOS,AWSS, or AWOS. At most airports with an operatingcontrol tower or human observer, the weather will beavailable to you in an Aviation Routine WeatherReport (METAR) hourly or special observationformat on the Automatic Terminal InformationService (ATIS) or directly transmitted from thecontroller/observer.
b. At uncontrolled airports that are equipped withASOS/AWSS/AWOS with ground−to−air broadcastcapability, the one−minute updated airport weathershould be available to you within approximately 25NM of the airport below 10,000 feet. The frequencyfor the weather broadcast will be published onsectional charts and in the Chart Supplement U.S.Some part−time towered airports may also broadcastthe automated weather on their ATIS frequencyduring the hours that the tower is closed.
c. Controllers issue SVFR or IFR clearancesbased on pilot request, known traffic and reportedweather, i.e., METAR/Nonroutine (Special) AviationWeather Report (SPECI) observations, when they areavailable. Pilots have access to more current weatherat uncontrolled ASOS/AWSS/AWOS airports thando the controllers who may be located several milesaway. Controllers will rely on the pilot to determinethe current airport weather from the ASOS/AWSS/AWOS. All aircraft arriving or departing anASOS/AWSS/AWOS equipped uncontrolled airportshould monitor the airport weather frequency toascertain the status of the airspace. Pilots in Class Eairspace must be alert for changing weatherconditions which may affect the status of the airspacefrom IFR/VFR. If ATC service is required forIFR/SVFR approach/departure or requested for VFRservice, the pilot should advise the controller thathe/she has received the one−minute weather and statehis/her intentions.
EXAMPLE−“I have the (airport) one−minute weather, request an ILSRunway 14 approach.”
a. A clearance issued by ATC is predicated onknown traffic and known physical airport conditions.An ATC clearance means an authorization by ATC,for the purpose of preventing collision betweenknown aircraft, for an aircraft to proceed underspecified conditions within controlled airspace. IT ISNOT AUTHORIZATION FOR A PILOT TODEVIATE FROM ANY RULE, REGULATION, ORMINIMUM ALTITUDE NOR TO CONDUCTUNSAFE OPERATION OF THE AIRCRAFT.
b. 14 CFR Section 91.3(a) states: “The pilot−in−command of an aircraft is directly responsible for,and is the final authority as to, the operation of thataircraft.” If ATC issues a clearance that would causea pilot to deviate from a rule or regulation, or in thepilot’s opinion, would place the aircraft in jeopardy,IT IS THE PILOT’S RESPONSIBILITY TOREQUEST AN AMENDED CLEARANCE. Simi-larly, if a pilot prefers to follow a different course ofaction, such as make a 360 degree turn for spacing tofollow traffic when established in a landing orapproach sequence, land on a different runway,takeoff from a different intersection, takeoff from thethreshold instead of an intersection, or delayoperation, THE PILOT IS EXPECTED TOINFORM ATC ACCORDINGLY. When the pilotrequests a different course of action, however, thepilot is expected to cooperate so as to precludedisruption of traffic flow or creation of conflictingpatterns. The pilot is also expected to usethe appropriate aircraft call sign to acknowledge allATC clearances, frequency changes, or advisoryinformation.
c. Each pilot who deviates from an ATC clearancein response to a Traffic Alert and Collision AvoidanceSystem resolution advisory must notify ATC of thatdeviation as soon as possible.
REFERENCE−Pilot/Controller Glossary Term− Traffic Alert and Collision AvoidanceSystem.
d. When weather conditions permit, during thetime an IFR flight is operating, it is the directresponsibility of the pilot to avoid other aircraft sinceVFR flights may be operating in the same areawithout the knowledge of ATC. Traffic clearances
provide standard separation only between IFRflights.
4−4−2. Clearance Prefix
A clearance, control information, or a response to arequest for information originated by an ATC facilityand relayed to the pilot through an air−to−groundcommunication station will be prefixed by “ATCclears,” “ATC advises,” or “ATC requests.”
4−4−3. Clearance Items
ATC clearances normally contain the following:
a. Clearance Limit. The traffic clearance issuedprior to departure will normally authorize flight to theairport of intended landing. Many airports andassociated NAVAIDs are collocated with the samename and/or identifier, so care should be exercised toensure a clear understanding of the clearance limit.When the clearance limit is the airport of intendedlanding, the clearance should contain the airportname followed by the word “airport.” Under certainconditions, a clearance limit may be a NAVAID orother fix. When the clearance limit is a NAVAID,intersection, or waypoint and the type is known, theclearance should contain type. Under certainconditions, at some locations a short−range clearanceprocedure is utilized whereby a clearance is issued toa fix within or just outside of the terminal area andpilots are advised of the frequency on which they willreceive the long−range clearance direct from thecenter controller.
b. Departure Procedure. Headings to fly andaltitude restrictions may be issued to separate adeparture from other air traffic in the terminal area.Where the volume of traffic warrants, DPs have beendeveloped.REFERENCE−AIM, Paragraph 5−2−5, Abbreviated IFR Departure Clearance(Cleared. . .as Filed) ProceduresAIM, Paragraph 5−2−8 , Instrument Departure Procedures (DP) −Obstacle Departure Procedures (ODP) and Standard InstrumentDepartures (SID)
c. Route of Flight.
1. Clearances are normally issued for thealtitude or flight level and route filed by the pilot.However, due to traffic conditions, it is frequentlynecessary for ATC to specify an altitude or flight level
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4−4−2 ATC Clearances and Aircraft Separation
or route different from that requested by the pilot. Inaddition, flow patterns have been established incertain congested areas or between congested areaswhereby traffic capacity is increased by routing alltraffic on preferred routes. Information on these flowpatterns is available in offices where preflightbriefing is furnished or where flight plans areaccepted.
2. When required, air traffic clearances includedata to assist pilots in identifying radio reportingpoints. It is the responsibility of pilots to notify ATCimmediately if their radio equipment cannot receivethe type of signals they must utilize to comply withtheir clearance.
d. Altitude Data.
1. The altitude or flight level instructions in anATC clearance normally require that a pilot“MAINTAIN” the altitude or flight level at which theflight will operate when in controlled airspace.Altitude or flight level changes while en route shouldbe requested prior to the time the change is desired.
2. When possible, if the altitude assigned isdifferent from the altitude requested by the pilot, ATCwill inform the pilot when to expect climb or descentclearance or to request altitude change from anotherfacility. If this has not been received prior to crossingthe boundary of the ATC facility’s area andassignment at a different altitude is still desired, thepilot should reinitiate the request with the nextfacility.
3. The term “cruise” may be used instead of“MAINTAIN” to assign a block of airspace to a pilotfrom the minimum IFR altitude up to and includingthe altitude specified in the cruise clearance. The pilotmay level off at any intermediate altitude within thisblock of airspace. Climb/descent within the block isto be made at the discretion of the pilot. However,once the pilot starts descent and verbally reportsleaving an altitude in the block, the pilot may notreturn to that altitude without additional ATCclearance.REFERENCE−Pilot/Controller Glossary Term− Cruise.
e. Holding Instructions.
1. Whenever an aircraft has been cleared to a fixother than the destination airport and delay isexpected, it is the responsibility of the ATC controllerto issue complete holding instructions (unless the
pattern is charted), an EFC time, and a best estimateof any additional en route/terminal delay.
2. If the holding pattern is charted and thecontroller doesn’t issue complete holding instruc-tions, the pilot is expected to hold as depicted on theappropriate chart. When the pattern is charted, thecontroller may omit all holding instructions exceptthe charted holding direction and the statementAS PUBLISHED, e.g., “HOLD EAST ASPUBLISHED.” Controllers must always issuecomplete holding instructions when pilots requestthem.
NOTE−Only those holding patterns depicted on U.S. governmentor commercially produced charts which meet FAArequirements should be used.
3. If no holding pattern is charted and holdinginstructions have not been issued, the pilot should askATC for holding instructions prior to reaching the fix.This procedure will eliminate the possibility of anaircraft entering a holding pattern other than thatdesired by ATC. If unable to obtain holdinginstructions prior to reaching the fix (due tofrequency congestion, stuck microphone, etc.), holdin a standard pattern on the course on which youapproached the fix and request further clearance assoon as possible. In this event, the altitude/flight levelof the aircraft at the clearance limit will be protectedso that separation will be provided as required.
4. When an aircraft is 3 minutes or less from aclearance limit and a clearance beyond the fix has notbeen received, the pilot is expected to start a speedreduction so that the aircraft will cross the fix,initially, at or below the maximum holding airspeed.
5. When no delay is expected, the controllershould issue a clearance beyond the fix as soon aspossible and, whenever possible, at least 5 minutesbefore the aircraft reaches the clearance limit.
6. Pilots should report to ATC the time andaltitude/flight level at which the aircraft reaches theclearance limit and report leaving the clearance limit.
NOTE−In the event of two−way communications failure, pilots arerequired to comply with 14 CFR Section 91.185.
4−4−4. Amended Clearances
a. Amendments to the initial clearance will beissued at any time an air traffic controller deems such
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action necessary to avoid possible conflictionbetween aircraft. Clearances will require that a flight“hold” or change altitude prior to reaching the pointwhere standard separation from other IFR trafficwould no longer exist.
NOTE−Some pilots have questioned this action and requested“traffic information” and were at a loss when the replyindicated “no traffic report.” In such cases the controllerhas taken action to prevent a traffic confliction whichwould have occurred at a distant point.
b. A pilot may wish an explanation of the handlingof the flight at the time of occurrence; however,controllers are not able to take time from theirimmediate control duties nor can they afford tooverload the ATC communications channels tofurnish explanations. Pilots may obtain an explana-tion by directing a letter or telephone call to the chiefcontroller of the facility involved.
c. Pilots have the privilege of requesting adifferent clearance from that which has been issuedby ATC if they feel that they have information whichwould make another course of action morepracticable or if aircraft equipment limitations orcompany procedures forbid compliance with theclearance issued.
4−4−5. Coded Departure Route (CDR)
a. CDRs provide air traffic control a rapid meansto reroute departing aircraft when the filed route isconstrained by either weather or congestion.
b. CDRs consist of an eight−character designatorthat represents a route of flight. The first threealphanumeric characters represent the departureairport, characters four through six represent thearrival airport, and the last two characters are chosenby the overlying ARTCC. For example, PITORDN1is an alternate route from Pittsburgh to Chicago.Participating aircrews may then be re−cleared by airtraffic control via the CDR abbreviated clearance,PITORDN1.
c. CDRs are updated on the 56 day charting cycle.Participating aircrews must ensure that their CDR iscurrent.
d. Traditionally, CDRs have been used by airtransport companies that have signed a Memorandumof Agreement with the local air traffic control facility.General aviation customers who wish to participate in
the program may now enter “CDR Capable” in theremarks section of their flight plan.
e. When “CDR Capable” is entered into theremarks section of the flight plan the general aviationcustomer communicates to ATC the ability to decodethe current CDR into a flight plan route and thewillingness to fly a different route than that whichwas filed.
4−4−6. Special VFR Clearances
a. An ATC clearance must be obtained prior tooperating within a Class B, Class C, Class D, orClass E surface area when the weather is less than thatrequired for VFR flight. A VFR pilot may request andbe given a clearance to enter, leave, or operate withinmost Class D and Class E surface areas and someClass B and Class C surface areas in special VFRconditions, traffic permitting, and providing suchflight will not delay IFR operations. All special VFRflights must remain clear of clouds. The visibilityrequirements for special VFR aircraft (other thanhelicopters) are:
1. At least 1 statute mile flight visibility foroperations within Class B, Class C, Class D, andClass E surface areas.
2. At least 1 statute mile ground visibility iftaking off or landing. If ground visibility is notreported at that airport, the flight visibility must be atleast 1 statute mile.
3. The restrictions in subparagraphs 1 and 2 donot apply to helicopters. Helicopters must remainclear of clouds and may operate in Class B, Class C,Class D, and Class E surface areas with less than1 statute mile visibility.
b. When a control tower is located within theClass B, Class C, or Class D surface area, requests forclearances should be to the tower. In a Class E surfacearea, a clearance may be obtained from the nearesttower, FSS, or center.
c. It is not necessary to file a complete flight planwith the request for clearance, but pilots should statetheir intentions in sufficient detail to permit ATC tofit their flight into the traffic flow. The clearance willnot contain a specific altitude as the pilot must remainclear of clouds. The controller may require the pilotto fly at or below a certain altitude due to other traffic,but the altitude specified will permit flight at or abovethe minimum safe altitude. In addition, at radar
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locations, flights may be vectored if necessary forcontrol purposes or on pilot request.
NOTE−The pilot is responsible for obstacle or terrain clearance.
d. Special VFR clearances are effective withinClass B, Class C, Class D, and Class E surface areasonly. ATC does not provide separation after anaircraft leaves the Class B, Class C, Class D, orClass E surface area on a special VFR clearance.
e. Special VFR operations by fixed−wing aircraftare prohibited in some Class B and Class C surfaceareas due to the volume of IFR traffic. A list of theseClass B and Class C surface areas is contained in14 CFR Part 91, Appendix D, Section 3. They arealso depicted on sectional aeronautical charts.
f. ATC provides separation between Special VFRflights and between these flights and other IFRflights.
g. Special VFR operations by fixed−wing aircraftare prohibited between sunset and sunrise unless thepilot is instrument rated and the aircraft is equippedfor IFR flight.
h. Pilots arriving or departing an uncontrolledairport that has automated weather broadcastcapability (ASOS/AWSS/AWOS) should monitorthe broadcast frequency, advise the controller thatthey have the “one−minute weather” and stateintentions prior to operating within the Class B, ClassC, Class D, or Class E surface areas.
4−4−7. Pilot Responsibility upon ClearanceIssuance
a. Record ATC clearance. When conducting anIFR operation, make a written record of yourclearance. The specified conditions which are a partof your air traffic clearance may be somewhatdifferent from those included in your flight plan.Additionally, ATC may find it necessary to ADDconditions, such as particular departure route. Thevery fact that ATC specifies different or additionalconditions means that other aircraft are involved inthe traffic situation.
b. ATC Clearance/Instruction Readback.Pilots of airborne aircraft should read backthose parts of ATC clearances and instructionscontaining altitude assignments, vectors, or runwayassignments as a means of mutual verification. Theread back of the “numbers” serves as a double checkbetween pilots and controllers and reduces the kindsof communications errors that occur when a numberis either “misheard” or is incorrect.
1. Include the aircraft identification in allreadbacks and acknowledgments. This aids control-lers in determining that the correct aircraft receivedthe clearance or instruction. The requirement toinclude aircraft identification in all readbacks andacknowledgements becomes more important asfrequency congestion increases and when aircraftwith similar call signs are on the same frequency.
EXAMPLE−“Climbing to Flight Level three three zero, United Twelve”or “November Five Charlie Tango, roger, cleared to landrunway nine left.”
2. Read back altitudes, altitude restrictions, andvectors in the same sequence as they are given in theclearance or instruction.
3. Altitudes contained in charted procedures,such as DPs, instrument approaches, etc., should notbe read back unless they are specifically stated by thecontroller.
4. Initial read back of a taxi, departure or landingclearance should include the runway assignment,including left, right, center, etc. if applicable.
c. It is the responsibility of the pilot to accept orrefuse the clearance issued.
4−4−8. IFR Clearance VFR−on−top
a. A pilot on an IFR flight plan operating in VFRweather conditions, may request VFR−on−top in lieuof an assigned altitude. This permits a pilot to selectan altitude or flight level of their choice (subject toany ATC restrictions.)
b. Pilots desiring to climb through a cloud, haze,smoke, or other meteorological formation and theneither cancel their IFR flight plan or operateVFR-on-top may request a climb to VFR-on-top. TheATC authorization must contain either a top report ora statement that no top report is available, and arequest to report reaching VFR-on-top. Additionally,the ATC authorization may contain a clearance limit,
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4−4−5ATC Clearances and Aircraft Separation
routing and an alternative clearance if VFR−on−topis not reached by a specified altitude.
c. A pilot on an IFR flight plan, operating in VFRconditions, may request to climb/descend in VFRconditions.
d. ATC may not authorize VFR−on−top/VFRconditions operations unless the pilot requests theVFR operation or a clearance to operate in VFRconditions will result in noise abatement benefitswhere part of the IFR departure route does notconform to an FAA approved noise abatement routeor altitude.
e. When operating in VFR conditions with an ATCauthorization to “maintain VFR−on−top/maintainVFR conditions” pilots on IFR flight plans must:
1. Fly at the appropriate VFR altitude asprescribed in 14 CFR Section 91.159.
2. Comply with the VFR visibility and distancefrom cloud criteria in 14 CFR Section 91.155 (BasicVFR Weather Minimums).
3. Comply with instrument flight rules that areapplicable to this flight; i.e., minimum IFR altitudes,position reporting, radio communications, course tobe flown, adherence to ATC clearance, etc.
NOTE−Pilots should advise ATC prior to any altitude change toensure the exchange of accurate traffic information.
f. ATC authorization to “maintain VFR−on−top”is not intended to restrict pilots so that they mustoperate only above an obscuring meteorologicalformation (layer). Instead, it permits operation above,below, between layers, or in areas where there is nometeorological obscuration. It is imperative, howev-er, that pilots understand that clearance to operate“VFR−on−top/VFR conditions” does not implycancellation of the IFR flight plan.
g. Pilots operating VFR−on−top/VFR conditionsmay receive traffic information from ATC on otherpertinent IFR or VFR aircraft. However, aircraftoperating in Class B airspace/TRSAs must beseparated as required by FAA Order JO 7110.65,Air Traffic Control.
NOTE−When operating in VFR weather conditions, it is the pilot’sresponsibility to be vigilant so as to see−and−avoid otheraircraft.
h. ATC will not authorize VFR or VFR−on−topoperations in Class A airspace.REFERENCE−AIM, Paragraph 3−2−2 , Class A Airspace
4−4−9. VFR/IFR Flights
A pilot departing VFR, either intending to or needingto obtain an IFR clearance en route, must be aware ofthe position of the aircraft and the relativeterrain/obstructions. When accepting a clearancebelow the MEA/MIA/MVA/OROCA, pilots areresponsible for their own terrain/obstruction clear-ance until reaching the MEA/MIA/MVA/OROCA. Ifpilots are unable to maintain terrain/obstructionclearance, the controller should be advised and pilotsshould state their intentions.
NOTE−OROCA is an off−route altitude which provides obstruc-tion clearance with a 1,000 foot buffer in nonmountainousterrain areas and a 2,000 foot buffer in designatedmountainous areas within the U.S. This altitude may notprovide signal coverage from ground−based navigationalaids, air traffic control radar, or communicationscoverage.
4−4−10. Adherence to Clearance
a. When air traffic clearance has been obtainedunder either visual or instrument flight rules, thepilot−in−command of the aircraft must not deviatefrom the provisions thereof unless an amendedclearance is obtained. When ATC issues a clearanceor instruction, pilots are expected to execute itsprovisions upon receipt. ATC, in certain situations,will include the word “IMMEDIATELY” in aclearance or instruction to impress urgency of animminent situation and expeditious compliance bythe pilot is expected and necessary for safety. Theaddition of a VFR or other restriction; i.e., climb ordescent point or time, crossing altitude, etc., does notauthorize a pilot to deviate from the route of flight orany other provision of the ATC clearance.
b. When a heading is assigned or a turn isrequested by ATC, pilots are expected to promptlyinitiate the turn, to complete the turn, and maintain thenew heading unless issued additional instructions.
c. The term “AT PILOT’S DISCRETION”included in the altitude information of an ATCclearance means that ATC has offered the pilot theoption to start climb or descent when the pilot wishes,
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4−4−6 ATC Clearances and Aircraft Separation
is authorized to conduct the climb or descent at anyrate, and to temporarily level off at any intermediatealtitude as desired. However, once the aircraft hasvacated an altitude, it may not return to that altitude.
d. When ATC has not used the term “AT PILOT’SDISCRETION” nor imposed any climb or descentrestrictions, pilots should initiate climb or descentpromptly on acknowledgement of the clearance.Descend or climb at an optimum rate consistent withthe operating characteristics of the aircraft to1,000 feet above or below the assigned altitude, andthen attempt to descend or climb at a rate of between500 and 1,500 fpm until the assigned altitude isreached. If at anytime the pilot is unable to climb ordescend at a rate of at least 500 feet a minute, adviseATC. If it is necessary to level off at an intermediatealtitude during climb or descent, advise ATC, exceptwhen leveling off at 10,000 feet MSL on descent, or2,500 feet above airport elevation (prior to entering aClass C or Class D surface area), when required forspeed reduction.
REFERENCE−14 CFR Section 91.117.
NOTE−Leveling off at 10,000 feet MSL on descent or 2,500 feetabove airport elevation (prior to entering a Class C orClass D surface area) to comply with 14 CFRSection 91.117 airspeed restrictions is commonplace.Controllers anticipate this action and plan accordingly.Leveling off at any other time on climb or descent mayseriously affect air traffic handling by ATC. Consequently,it is imperative that pilots make every effort to fulfill theabove expected actions to aid ATC in safely handling andexpediting traffic.
e. If the altitude information of an ATCDESCENT clearance includes a provision to“CROSS (fix) AT” or “AT OR ABOVE/BELOW(altitude),” the manner in which the descent isexecuted to comply with the crossing altitude is at thepilot’s discretion. This authorization to descend atpilot’s discretion is only applicable to that portion ofthe flight to which the crossing altitude restrictionapplies, and the pilot is expected to comply with thecrossing altitude as a provision of the clearance. Anyother clearance in which pilot execution is optionalwill so state “AT PILOT’S DISCRETION.”
EXAMPLE−1. “United Four Seventeen, descend and maintainsix thousand.”
NOTE−1. The pilot is expected to commence descent upon receiptof the clearance and to descend at the suggested rates untilreaching the assigned altitude of 6,000 feet.
EXAMPLE−2. “United Four Seventeen, descend at pilot’s discretion,maintain six thousand.”
NOTE−2. The pilot is authorized to conduct descent within thecontext of the term at pilot’s discretion as described above.
EXAMPLE−3. “United Four Seventeen, cross Lakeview V−O−R at orabove Flight Level two zero zero, descend and maintainsix thousand.”
NOTE−3. The pilot is authorized to conduct descent at pilot’sdiscretion until reaching Lakeview VOR and must complywith the clearance provision to cross the Lakeview VOR ator above FL 200. After passing Lakeview VOR, the pilot isexpected to descend at the suggested rates until reachingthe assigned altitude of 6,000 feet.
EXAMPLE−4. “United Four Seventeen, cross Lakeview V−O−R atsix thousand, maintain six thousand.”
NOTE−4. The pilot is authorized to conduct descent at pilot’sdiscretion, however, must comply with the clearanceprovision to cross the Lakeview VOR at 6,000 feet.
EXAMPLE−5. “United Four Seventeen, descend now to FlightLevel two seven zero, cross Lakeview V−O−R at or belowone zero thousand, descend and maintain six thousand.”
NOTE−5. The pilot is expected to promptly execute and completedescent to FL 270 upon receipt of the clearance. Afterreaching FL 270 the pilot is authorized to descend “atpilot’s discretion” until reaching Lakeview VOR. The pilotmust comply with the clearance provision to crossLakeview VOR at or below 10,000 feet. After LakeviewVOR the pilot is expected to descend at the suggested ratesuntil reaching 6,000 feet.
EXAMPLE−6. “United Three Ten, descend now and maintain FlightLevel two four zero, pilot’s discretion after reaching FlightLevel two eight zero.”
NOTE−6. The pilot is expected to commence descent upon receiptof the clearance and to descend at the suggested rates untilreaching FL 280. At that point, the pilot is authorized tocontinue descent to FL 240 within the context of the term“at pilot’s discretion” as described above.
f. In case emergency authority is used to deviatefrom provisions of an ATC clearance, the pilot−in−
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command must notify ATC as soon as possible andobtain an amended clearance. In an emergencysituation which does not result in a deviation from therules prescribed in 14 CFR Part 91 but which requiresATC to give priority to an aircraft, the pilot of suchaircraft must, when requested by ATC, make a reportwithin 48 hours of such emergency situation to themanager of that ATC facility.
g. The guiding principle is that the last ATCclearance has precedence over the previous ATCclearance. When the route or altitude in a previouslyissued clearance is amended, the controller willrestate applicable altitude restrictions. If altitude tomaintain is changed or restated, whether prior todeparture or while airborne, and previously issuedaltitude restrictions are omitted, those altituderestrictions are canceled, including departure proce-dures and STAR altitude restrictions.
EXAMPLE−1. A departure flight receives a clearance to destinationairport to maintain FL 290. The clearance incorporates aDP which has certain altitude crossing restrictions. Shortlyafter takeoff, the flight receives a new clearance changingthe maintaining FL from 290 to 250. If the altituderestrictions are still applicable, the controller restatesthem.
2. A departing aircraft is cleared to cross FlukyIntersection at or above 3,000 feet, Gordonville VOR at orabove 12,000 feet, maintain FL 200. Shortly afterdeparture, the altitude to be maintained is changed toFL 240. If the altitude restrictions are still applicable, thecontroller issues an amended clearance as follows: “crossFluky Intersection at or above three thousand, crossGordonville V−O−R at or above one two thousand,maintain Flight Level two four zero.”
3. An arriving aircraft is cleared to the destination airportvia V45 Delta VOR direct; the aircraft is cleared to crossDelta VOR at 10,000 feet, and then to maintain 6,000 feet.Prior to Delta VOR, the controller issues an amendedclearance as follows: “turn right heading one eight zerofor vector to runway three six I−L−S approach, maintainsix thousand.”
NOTE−Because the altitude restriction “cross Delta V−O−R at10,000 feet” was omitted from the amended clearance, it isno longer in effect.
h. Pilots of turbojet aircraft equipped withafterburner engines should advise ATC prior totakeoff if they intend to use afterburning during theirclimb to the en route altitude. Often, the controller
may be able to plan traffic to accommodate a highperformance climb and allow the aircraft to climb tothe planned altitude without restriction.
i. If an “expedite” climb or descent clearance isissued by ATC, and the altitude to maintain issubsequently changed or restated without an expediteinstruction, the expedite instruction is canceled.Expedite climb/descent normally indicates to thepilot that the approximate best rate of climb/descentshould be used without requiring an exceptionalchange in aircraft handling characteristics. Normallycontrollers will inform pilots of the reason for aninstruction to expedite.
4−4−11. IFR Separation Standards
a. ATC effects separation of aircraft vertically byassigning different altitudes; longitudinally byproviding an interval expressed in time or distancebetween aircraft on the same, converging, or crossingcourses, and laterally by assigning different flightpaths.
b. Separation will be provided between all aircraftoperating on IFR flight plans except during that partof the flight (outside Class B airspace or a TRSA)being conducted on a VFR−on−top/VFR conditionsclearance. Under these conditions, ATC may issuetraffic advisories, but it is the sole responsibility of thepilot to be vigilant so as to see and avoid other aircraft.
c. When radar is employed in the separation ofaircraft at the same altitude, a minimum of 3 milesseparation is provided between aircraft operatingwithin 40 miles of the radar antenna site, and 5 milesbetween aircraft operating beyond 40 miles from theantenna site. These minima may be increased ordecreased in certain specific situations.
NOTE−Certain separation standards are increased in the terminalenvironment when CENRAP is being utilized.
4−4−12. Speed Adjustments
a. ATC will issue speed adjustments to pilots ofradar−controlled aircraft to achieve or maintainrequired or desire spacing.
b. ATC will express all speed adjustments interms of knots based on indicated airspeed (IAS) in5 or 10 knot increments except that at or above FL240 speeds may be expressed in terms of Machnumbers in 0.01 increments. The use of Mach
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4−4−8 ATC Clearances and Aircraft Separation
numbers is restricted to turbojet aircraft with Machmeters.
c. Pilots complying with speed adjustments areexpected to maintain a speed within plus or minus10 knots or 0.02 Mach number of the specified speed.
d. When ATC assigns speed adjustments, it willbe in accordance with the following recommendedminimums:
1. To aircraft operating between FL 280 and10,000 feet, a speed not less than 250 knots or theequivalent Mach number.
NOTE−1. On a standard day the Mach numbers equivalent to250 knots CAS (subject to minor variations) are:FL 240−0.6FL 250−0.61FL 260−0.62FL 270−0.64FL 280−0.65FL 290−0.66.
2. When an operational advantage will be realized, speedslower than the recommended minima may be applied.
2. To arriving turbojet aircraft operating below10,000 feet:
(a) A speed not less than 210 knots, except;
(b) Within 20 flying miles of the airport ofintended landing, a speed not less than 170 knots.
3. To arriving reciprocating engine or turbopropaircraft within 20 flying miles of the runwaythreshold of the airport of intended landing, a speednot less than 150 knots.
4. To departing aircraft:
(a) Turbojet aircraft, a speed not less than230 knots.
(b) Reciprocating engine aircraft, a speed notless than 150 knots.
e. When ATC combines a speed adjustment witha descent clearance, the sequence of delivery, with theword “then” between, indicates the expected order ofexecution.
EXAMPLE−1. Descend and maintain (altitude); then, reduce speed to(speed).
2. Reduce speed to (speed); then, descend and maintain(altitude).
NOTE−The maximum speeds below 10,000 feet as established in14 CFR Section 91.117 still apply. If there is any doubtconcerning the manner in which such a clearance is to beexecuted, request clarification from ATC.
f. If ATC determines (before an approachclearance is issued) that it is no longer necessary toapply speed adjustment procedures, they will:
1. Advise the pilot to “resume normal speed.”Normal speed is used to terminate ATC assignedspeed adjustments on segments where no publishedspeed restrictions apply. It does not cancel publishedrestrictions on upcoming procedures. This does notrelieve the pilot of those speed restrictions which areapplicable to 14 CFR Section 91.117.
EXAMPLE−(An aircraft is flying a SID with no published speedrestrictions. ATC issues a speed adjustment and instructsthe aircraft where the adjustment ends): “Maintain two twozero knots until BALTR then resume normal speed.”
NOTE−The ATC assigned speed assignment of two two zero knotswould apply until BALTR. The aircraft would then resumea normal operating speed while remaining in compliancewith 14 CFR Section 91.117.
2. Instruct pilots to “comply with speedrestrictions” when the aircraft is joining or resuminga charted procedure or route with published speedrestrictions.
EXAMPLE−(ATC vectors an aircraft off of a SID to rejoin the procedureat a subsequent waypoint. When instructing the aircraft toresume the procedure, ATC also wants the aircraft tocomply with the published procedure speed restrictions):“Resume the SALTY ONE departure. Comply with speedrestrictions.”
CAUTION−The phraseology “Descend via/Climb via SID” requirescompliance with all altitude and/or speed restrictionsdepicted on the procedure.
3. Instruct the pilot to “resume publishedspeed.” Resume published speed is issued toterminate a speed adjustment where speed restric-tions are published on a charted procedure.
NOTE−When instructed to “comply with speed restrictions” or to“resume published speed,” ATC anticipates pilots willbegin adjusting speed the minimum distance necessaryprior to a published speed restriction so as to cross thewaypoint/fix at the published speed. Once at the published
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speed, ATC expects pilots will maintain the publishedspeed until additional adjustment is required to complywith further published or ATC assigned speed restrictionsor as required to ensure compliance with 14 CFRSection 91.117.
EXAMPLE−(An aircraft is flying a SID/STAR with published speedrestrictions. ATC issues a speed adjustment and instructsthe aircraft where the adjustment ends): “Maintain two twozero knots until BALTR then resume published speed.”
NOTE−The ATC assigned speed assignment of two two zero knotswould apply until BALTR. The aircraft would then complywith the published speed restrictions.
4. Advise the pilot to “delete speed restrictions”when either ATC assigned or published speedrestrictions on a charted procedure are no longerrequired.
EXAMPLE−(An aircraft is flying a SID with published speedrestrictions designed to prevent aircraft overtake ondeparture. ATC determines there is no conflicting trafficand deletes the speed restriction): “Delete speedrestrictions.”
NOTE−When deleting published restrictions, ATC must ensureobstacle clearance until aircraft are established on a routewhere no published restrictions apply. This does not relievethe pilot of those speed restrictions which are applicable to14 CFR Section 91.117.
5. Instruct the pilot to “climb via” or “descendvia.” A climb via or descend via clearance cancels anypreviously issued speed restrictions and, onceestablished on the depicted departure or arrival, toclimb or descend, and to meet all published orassigned altitude and/or speed restrictions.
EXAMPLE−1. (An aircraft is flying a SID with published speedrestrictions. ATC has issued a speed restriction of 250 knotsfor spacing. ATC determines that spacing between aircraftis adequate and desires the aircraft to comply withpublished restrictions): “United 436, Climb via SID.”
2. (An aircraft is established on a STAR. ATC must slow anaircraft for the purposes of spacing and assigns it a speedof 280 knots. When spacing is adequate, ATC deletes thespeed restriction and desires that the aircraft comply withall published restrictions on the STAR): “Gulfstream twothree papa echo, descend via the TYLER One arrival.”
NOTE−1. In example 1, when ATC issues a “Climb via SID”clearance, it deletes any previously issued speed and/or
altitude restrictions. The pilot should then verticallynavigate to comply with all speed and/or altituderestrictions published on the SID.
2. In example 2, when ATC issues a “Descend via <STARname> arrival,” ATC has canceled any previously issuedspeed and/or altitude restrictions. The pilot shouldvertically navigate to comply with all speed and/or altituderestrictions published on the STAR.
CAUTION−When descending on a STAR, pilots should not speed upexcessively beyond the previously issued speed. Otherwise,adequate spacing between aircraft descending on the STARthat was established by ATC with the previous restrictionmay be lost.
g. Approach clearances supersede any prior speedadjustment assignments, and pilots are expected tomake their own speed adjustments as necessary tocomplete the approach. However, under certaincircumstances, it may be necessary for ATC to issuefurther speed adjustments after approach clearance isissued to maintain separation between successivearrivals. Under such circumstances, previouslyissued speed adjustments will be restated if that speedis to be maintained or additional speed adjustmentsare requested. Speed adjustments should not beassigned inside the final approach fix on final or apoint 5 miles from the runway, whichever is closer tothe runway.
h. The pilots retain the prerogative of rejecting theapplication of speed adjustment by ATC if theminimum safe airspeed for any particular operation isgreater than the speed adjustment.
NOTE−In such cases, pilots are expected to advise ATC of thespeed that will be used.
i. Pilots are reminded that they are responsible forrejecting the application of speed adjustment by ATCif, in their opinion, it will cause them to exceed themaximum indicated airspeed prescribed by 14 CFRSection 91.117(a), (c) and (d). IN SUCH CASES,THE PILOT IS EXPECTED TO SO INFORM ATC.Pilots operating at or above 10,000 feet MSL who areissued speed adjustments which exceed 250 knotsIAS and are subsequently cleared below 10,000 feetMSL are expected to comply with 14 CFRSection 91.117(a).
j. Speed restrictions of 250 knots do not apply toU.S. registered aircraft operating beyond 12 nauticalmiles from the coastline within the U.S. Flight
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4−4−10 ATC Clearances and Aircraft Separation
Information Region, in Class E airspace below10,000 feet MSL. However, in airspace underlying aClass B airspace area designated for an airport, or ina VFR corridor designated through such as a Class Bairspace area, pilots are expected to comply with the200 knot speed limit specified in 14 CFRSection 91.117(c).
k. For operations in a Class C and Class D surfacearea, ATC is authorized to request or approve a speedgreater than the maximum indicated airspeedsprescribed for operation within that airspace (14 CFRSection 91.117(b)).
NOTE−Pilots are expected to comply with the maximum speed of200 knots when operating beneath Class B airspace or ina Class B VFR corridor (14 CFR Section 91.117(c)and (d)).
l. When in communications with the ARTCC orapproach control facility, pilots should, as a goodoperating practice, state any ATC assigned speedrestriction on initial radio contact associated with anATC communications frequency change.
4−4−13. Runway Separation
Tower controllers establish the sequence of arrivingand departing aircraft by requiring them to adjustflight or ground operation as necessary to achieveproper spacing. They may “HOLD” an aircraft shortof the runway to achieve spacing between it and anarriving aircraft; the controller may instruct a pilot to“EXTEND DOWNWIND” in order to establishspacing from an arriving or departing aircraft. Attimes a clearance may include the word “IMMEDI-ATE.” For example: “CLEARED FORIMMEDIATE TAKEOFF.” In such cases “IMMEDI-ATE” is used for purposes of air traffic separation. Itis up to the pilot to refuse the clearance if, in the pilot’sopinion, compliance would adversely affect theoperation.
REFERENCE−AIM, Paragraph 4−3−15 , Gate Holding due to Departure Delays
4−4−14. Visual Separation
a. Visual separation is a means employed by ATCto separate aircraft in terminal areas and en routeairspace in the NAS. There are two methodsemployed to effect this separation:
1. The tower controller sees the aircraftinvolved and issues instructions, as necessary, toensure that the aircraft avoid each other.
2. A pilot sees the other aircraft involved andupon instructions from the controller providesseparation by maneuvering the aircraft to avoid it.When pilots accept responsibility to maintain visualseparation, they must maintain constant visualsurveillance and not pass the other aircraft until it isno longer a factor.
NOTE−Traffic is no longer a factor when during approach phasethe other aircraft is in the landing phase of flight orexecutes a missed approach; and during departure oren route, when the other aircraft turns away or is on adiverging course.
b. A pilot’s acceptance of instructions to followanother aircraft or provide visual separation from it isan acknowledgment that the pilot will maneuver theaircraft as necessary to avoid the other aircraft or tomaintain in−trail separation. In operations conductedbehind heavy aircraft, or a small aircraft behind aB757 or other large aircraft, it is also anacknowledgment that the pilot accepts the responsi-bility for wake turbulence separation. Visualseparation is prohibited behind super aircraft.
NOTE−When a pilot has been told to follow another aircraft or toprovide visual separation from it, the pilot should promptlynotify the controller if visual contact with the other aircraftis lost or cannot be maintained or if the pilot cannot acceptthe responsibility for the separation for any reason.
c. Scanning the sky for other aircraft is a key factorin collision avoidance. Pilots and copilots (or the rightseat passenger) should continuously scan to cover allareas of the sky visible from the cockpit. Pilots mustdevelop an effective scanning technique whichmaximizes one’s visual capabilities. Spotting apotential collision threat increases directly as moretime is spent looking outside the aircraft. One mustuse timesharing techniques to effectively scan thesurrounding airspace while monitoring instrumentsas well.
d. Since the eye can focus only on a narrowviewing area, effective scanning is accomplishedwith a series of short, regularly spaced eyemovements that bring successive areas of the sky intothe central visual field. Each movement should notexceed ten degrees, and each area should be observedfor at least one second to enable collision detection.
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Although many pilots seem to prefer the method ofhorizontal back−and−forth scanning every pilotshould develop a scanning pattern that is not onlycomfortable but assures optimum effectiveness.Pilots should remember, however, that they have aregulatory responsibility (14 CFR Section 91.113(a))to see and avoid other aircraft when weatherconditions permit.
4−4−15. Use of Visual Clearing Procedures
a. Before Takeoff. Prior to taxiing onto a runwayor landing area in preparation for takeoff, pilotsshould scan the approach areas for possible landingtraffic and execute the appropriate clearing maneu-vers to provide them a clear view of the approachareas.
b. Climbs and Descents. During climbs anddescents in flight conditions which permit visualdetection of other traffic, pilots should execute gentlebanks, left and right at a frequency which permitscontinuous visual scanning of the airspace aboutthem.
c. Straight and Level. Sustained periods ofstraight and level flight in conditions which permitvisual detection of other traffic should be broken atintervals with appropriate clearing procedures toprovide effective visual scanning.
d. Traffic Pattern. Entries into traffic patternswhile descending create specific collision hazardsand should be avoided.
e. Traffic at VOR Sites. All operators shouldemphasize the need for sustained vigilance in thevicinity of VORs and airway intersections due to theconvergence of traffic.
f. Training Operations. Operators of pilot train-ing programs are urged to adopt the followingpractices:
1. Pilots undergoing flight instruction at alllevels should be requested to verbalize clearingprocedures (call out “clear” left, right, above, orbelow) to instill and sustain the habit of vigilanceduring maneuvering.
2. High−wing airplane. Momentarily raise thewing in the direction of the intended turn and look.
3. Low−wing airplane. Momentarily lowerthe wing in the direction of the intended turn and look.
4. Appropriate clearing procedures shouldprecede the execution of all turns includingchandelles, lazy eights, stalls, slow flight, climbs,straight and level, spins, and other combinationmaneuvers.
4−4−16. Traffic Alert and CollisionAvoidance System (TCAS I & II)
a. TCAS I provides proximity warning only, toassist the pilot in the visual acquisition of intruderaircraft. No recommended avoidance maneuvers areprovided nor authorized as a direct result of a TCAS Iwarning. It is intended for use by smaller commuteraircraft holding 10 to 30 passenger seats, and generalaviation aircraft.
b. TCAS II provides traffic advisories (TAs) andresolution advisories (RAs). Resolution advisoriesprovide recommended maneuvers in a verticaldirection (climb or descend only) to avoid conflictingtraffic. Airline aircraft, and larger commuter andbusiness aircraft holding 31 passenger seats or more,use TCAS II equipment.
1. Each pilot who deviates from an ATCclearance in response to a TCAS II RA must notifyATC of that deviation as soon as practicable andexpeditiously return to the current ATC clearancewhen the traffic conflict is resolved.
2. Deviations from rules, policies, or clearancesshould be kept to the minimum necessary to satisfy aTCAS II RA.
3. The serving IFR air traffic facility is notresponsible to provide approved standard IFRseparation to an aircraft after a TCAS II RA maneuveruntil one of the following conditions exists:
(a) The aircraft has returned to its assignedaltitude and course.
(b) Alternate ATC instructions have beenissued.
c. TCAS does not alter or diminish the pilot’s basicauthority and responsibility to ensure safe flight.Since TCAS does not respond to aircraft which arenot transponder equipped or aircraft with atransponder failure, TCAS alone does not ensure safeseparation in every case.
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d. At this time, no air traffic service nor handlingis predicated on the availability of TCAS equipmentin the aircraft.
4−4−17. Traffic Information Service (TIS)
a. TIS provides proximity warning only, to assistthe pilot in the visual acquisition of intruder aircraft.No recommended avoidance maneuvers are providednor authorized as a direct result of a TIS intruderdisplay or TIS alert. It is intended for use by aircraftin which TCAS is not required.
b. TIS does not alter or diminish the pilot’s basicauthority and responsibility to ensure safe flight.
Since TIS does not respond to aircraft which are nottransponder equipped, aircraft with a transponderfailure, or aircraft out of radar coverage, TIS alonedoes not ensure safe separation in every case.
c. At this time, no air traffic service nor handlingis predicated on the availability of TIS equipment inthe aircraft.
d. Presently, no air traffic services or handling ispredicated on the availability of an ADS−B cockpitdisplay. A “traffic−in−sight” reply to ATC must bebased on seeing an aircraft out−the−window, NOT onthe cockpit display.
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4−5−1Surveillance Systems
Section 5. Surveillance Systems
4−5−1. Radar
a. Capabilities
1. Radar is a method whereby radio waves aretransmitted into the air and are then received whenthey have been reflected by an object in the path of thebeam. Range is determined by measuring the time ittakes (at the speed of light) for the radio wave to goout to the object and then return to the receivingantenna. The direction of a detected object from aradar site is determined by the position of the rotatingantenna when the reflected portion of the radio waveis received.
2. More reliable maintenance and improvedequipment have reduced radar system failures to anegligible factor. Most facilities actually have somecomponents duplicated, one operating and anotherwhich immediately takes over when a malfunctionoccurs to the primary component.
b. Limitations
1. It is very important for the aviationcommunity to recognize the fact that there arelimitations to radar service and that ATC controllersmay not always be able to issue traffic advisoriesconcerning aircraft which are not under ATC controland cannot be seen on radar. (See FIG 4−5−1.)
FIG 4−5−1Limitations to Radar Service
Precipitation Attenuation
The nearby target absorbs and scatters so much of the out-going and returning
energy that the radar does not detect the distant target.
AREA BLACKED OUTBY ATTENUATION
NOT OBSERVED
OBSERVEDECHO
(a) The characteristics of radio waves aresuch that they normally travel in a continuous straightline unless they are:
(1) “Bent” by abnormal atmospheric phe-nomena such as temperature inversions;
(2) Reflected or attenuated by denseobjects such as heavy clouds, precipitation, groundobstacles, mountains, etc.; or
(3) Screened by high terrain features.
(b) The bending of radar pulses, often calledanomalous propagation or ducting, may cause manyextraneous blips to appear on the radar operator’sdisplay if the beam has been bent toward the groundor may decrease the detection range if the wave isbent upward. It is difficult to solve the effects ofanomalous propagation, but using beacon radar andelectronically eliminating stationary and slowmoving targets by a method called moving targetindicator (MTI) usually negate the problem.
(c) Radar energy that strikes dense objectswill be reflected and displayed on the operator’sscope thereby blocking out aircraft at the same rangeand greatly weakening or completely eliminating thedisplay of targets at a greater range. Again, radarbeacon and MTI are very effectively used to combatground clutter and weather phenomena, and a methodof circularly polarizing the radar beam will eliminatesome weather returns. A negative characteristic ofMTI is that an aircraft flying a speed that coincideswith the canceling signal of the MTI (tangential or“blind” speed) may not be displayed to the radarcontroller.
(d) Relatively low altitude aircraft will not beseen if they are screened by mountains or are belowthe radar beam due to earth curvature. The onlysolution to screening is the installation of strategi-cally placed multiple radars which has been done insome areas.
(e) There are several other factors whichaffect radar control. The amount of reflective surfaceof an aircraft will determine the size of the radarreturn. Therefore, a small light airplane or a sleek jetfighter will be more difficult to see on radar than alarge commercial jet or military bomber. Here again,the use of radar beacon is invaluable if the aircraft is
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4−5−2 Surveillance Systems
equipped with an airborne transponder. All ARTCCs’radars in the conterminous U.S. and many airportsurveillance radars have the capability to interrogateMode C and display altitude information to thecontroller from appropriately equipped aircraft.However, there are a number of airport surveillanceradars that don’t have Mode C display capability and;therefore, altitude information must be obtained fromthe pilot.
(f) At some locations within the ATC en routeenvironment, secondary−radar−only (no primaryradar) gap filler radar systems are used to give loweraltitude radar coverage between two larger radarsystems, each of which provides both primary andsecondary radar coverage. In those geographicalareas served by secondary−radar only, aircraftwithout transponders cannot be provided with radarservice. Additionally, transponder equipped aircraftcannot be provided with radar advisories concerningprimary targets and weather.
REFERENCE−Pilot/Controller Glossary Term− Radar.
(g) The controller’s ability to advise a pilotflying on instruments or in visual conditions of theaircraft’s proximity to another aircraft will be limitedif the unknown aircraft is not observed on radar, if noflight plan information is available, or if the volumeof traffic and workload prevent issuing trafficinformation. The controller’s first priority is given toestablishing vertical, lateral, or longitudinal separa-tion between aircraft flying IFR under the control ofATC.
c. FAA radar units operate continuously at thelocations shown in the Chart Supplement U.S., andtheir services are available to all pilots, both civil andmilitary. Contact the associated FAA control tower orARTCC on any frequency guarded for initialinstructions, or in an emergency, any FAA facility forinformation on the nearest radar service.
4−5−2. Air Traffic Control Radar BeaconSystem (ATCRBS)
a. The ATCRBS, sometimes referred to assecondary surveillance radar, consists of three maincomponents:
1. Interrogator. Primary radar relies on asignal being transmitted from the radar antenna siteand for this signal to be reflected or “bounced back”
from an object (such as an aircraft). This reflectedsignal is then displayed as a “target” on thecontroller’s radarscope. In the ATCRBS, theInterrogator, a ground based radar beacon transmit-ter−receiver, scans in synchronism with the primaryradar and transmits discrete radio signals whichrepetitiously request all transponders, on the modebeing used, to reply. The replies received are thenmixed with the primary returns and both aredisplayed on the same radarscope.
2. Transponder. This airborne radar beacontransmitter−receiver automatically receives the sig-nals from the interrogator and selectively replies witha specific pulse group (code) only to thoseinterrogations being received on the mode to whichit is set. These replies are independent of, and muchstronger than a primary radar return.
3. Radarscope. The radarscope used by thecontroller displays returns from both the primaryradar system and the ATCRBS. These returns, calledtargets, are what the controller refers to in the controland separation of traffic.
b. The job of identifying and maintainingidentification of primary radar targets is a long andtedious task for the controller. Some of theadvantages of ATCRBS over primary radar are:
1. Reinforcement of radar targets.
2. Rapid target identification.
3. Unique display of selected codes.
c. A part of the ATCRBS ground equipment is thedecoder. This equipment enables a controller toassign discrete transponder codes to each aircraftunder his/her control. Normally only one code will beassigned for the entire flight. Assignments are madeby the ARTCC computer on the basis of the NationalBeacon Code Allocation Plan. The equipment is alsodesigned to receive Mode C altitude informationfrom the aircraft.NOTE−Refer to figures with explanatory legends for an illustrationof the target symbology depicted on radar scopes in theNAS Stage A (en route), the ARTS III (terminal) Systems,and other nonautomated (broadband) radar systems. (SeeFIG 4−5−2 and FIG 4−5−3.)
d. It should be emphasized that aircraft transpond-ers greatly improve the effectiveness of radarsystems.REFERENCE−AIM, Paragraph 4−1−20 , Transponder Operation
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4−5−3Surveillance Systems
FIG 4−5−2ARTS III Radar Scope With Alphanumeric Data
NOTE−A number of radar terminals do not have ARTS equipment. Those facilities and certain ARTCCs outside the contiguous U.S.would have radar displays similar to the lower right hand subset. ARTS facilities and NAS Stage A ARTCCs, when operatingin the nonautomation mode, would also have similar displays and certain services based on automation may not beavailable.
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EXAMPLE−
1. Areas of precipitation (can be reduced by CP)
2. Arrival/departure tabular list
3. Trackball (control) position symbol (A)
4. Airway (lines are sometimes deleted in part)
5. Radar limit line for control
6. Obstruction (video map)
7. Primary radar returns of obstacles or terrain (can beremoved by MTI)
8. Satellite airports
9. Runway centerlines (marks and spaces indicatemiles)
10. Primary airport with parallel runways
11. Approach gates
12. Tracked target (primary and beacon target)
13. Control position symbol
14. Untracked target select code (monitored) withMode C readout of 5,000’
15. Untracked target without Mode C
16. Primary target
17. Beacon target only (secondary radar) (transponder)
18. Primary and beacon target
19. Leader line
20. Altitude Mode C readout is 6,000’ (Note: readouts may not be displayed because ofnonreceipt of beacon information, garbled beaconsignals, and flight plan data which is displayedalternately with the altitude readout)
21. Ground speed readout is 240 knots (Note: readouts may not be displayed because of a lossof beacon signal, a controller alert that a pilot wassquawking emergency, radio failure, etc.)
22. Aircraft ID
23. Asterisk indicates a controller entry in Mode Cblock. In this case 5,000’ is entered and “05” wouldalternate with Mode C readout.
24. Indicates heavy
25. “Low ALT” flashes to indicate when an aircraft’spredicted descent places the aircraft in an unsafeproximity to terrain. (Note: this feature does not function if the aircraft is notsquawking Mode C. When a helicopter or aircraft isknown to be operating below the lower safe limit, the“low ALT” can be changed to “inhibit” and flashingceases.)
26. NAVAIDs
27. Airways
28. Primary target only
29. Nonmonitored. No Mode C (an asterisk wouldindicate nonmonitored with Mode C)
30. Beacon target only (secondary radar based onaircraft transponder)
31. Tracked target (primary and beacon target) controlposition A
32. Aircraft is squawking emergency Code 7700 and isnonmonitored, untracked, Mode C
33. Controller assigned runway 36 right alternates withMode C readout (Note: a three letter identifier could also indicate thearrival is at specific airport)
34. Ident flashes
35. Identing target blossoms
36. Untracked target identing on a selected code
37. Range marks (10 and 15 miles) (can bechanged/offset)
38. Aircraft controlled by center
39. Targets in suspend status
40. Coast/suspend list (aircraft holding, temporary lossof beacon/target, etc.)
41. Radio failure (emergency information)
42. Select beacon codes (being monitored)
43. General information (ATIS, runway, approach inuse)
44. Altimeter setting
45. Time
46. System data area
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FIG 4−5−3NAS Stage A Controllers View Plan Display
This figure illustrates the controller’s radar scope (PVD) when operating in the full automation (RDP) mode, which isnormally 20 hours per day.
(When not in automation mode, the display is similar to the broadband mode shown in the ARTS III radar scope figure.Certain ARTCCs outside the contiguous U.S. also operate in “broadband” mode.)
2526
X
XXXX
XXXX
#
X
X
X
AAL373280C191H-33
AAL373280C191H-33
VIG123310N095
VIG123310N095
NWA258170 143NWA258170 143
AAL35370 2312734
AAL35370 2312734
R15909170CR15909170C290
21032902103
N1467F140 + 143460
N1467F140 + 143460
UAL33100A296
UAL33100A296
7700EMRG7700EMRG
7600RDOF7600RDOF
1200
120085
120085
+ + ++ UAL712
310N228CST
UAL712310N
228CST
1
22 23
2427
28
29
29
30
2
3
4
5
6
7
8
9
1011
12
13
14
15
16
1718
1920
21
H
HH
HH
HH
H
H HHH
H
RADAR SERVICES AND PROCEDURES
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EXAMPLE−Target symbols:
1. Uncorrelated primary radar target [!] [+]
2. Correlated primary radar target [#] "See note below.
3. Uncorrelated beacon target [ / ]
4. Correlated beacon target [ \ ]
5. Identing beacon target [!]
"Note: in Number 2 correlated means the association ofradar data with the computer projected track of anidentified aircraft.
Position symbols:
6. Free track (no flight plan tracking) [$]
7. Flat track (flight plan tracking) [!]
8. Coast (beacon target lost) [#]
9. Present position hold [ # ]
Data block information:
10. Aircraft ident "See note below.
11. Assigned altitude FL 280, Mode C altitude same orwithin % 200’ of assigned altitude. "See note below.
12. Computer ID #191, handoff is to sector 33 (0−33 would mean handoff accepted) "See note below.
13. Assigned altitude 17,000’, aircraft is climbing,Mode C readout was 14,300 when last beacon interroga-tion was received.
14. Leader line connecting target symbol and data block
15. Track velocity and direction vector line (projectedahead of target)
16. Assigned altitude 7,000, aircraft is descending, lastMode C readout (or last reported altitude) was 100’ aboveFL 230
17. Transponder code shows in full data block only whendifferent than assigned code
18. Aircraft is 300’ above assigned altitude
19. Reported altitude (no Mode C readout) same asassigned. (An “n” would indicate no reported altitude.)
20. Transponder set on emergency Code 7700 (EMRGflashes to attract attention)
21. Transponder Code 1200 (VFR) with no Mode C
22. Code 1200 (VFR) with Mode C and last altitudereadout
23. Transponder set on radio failure Code 7600 (RDOFflashes)
24. Computer ID #228, CST indicates target is in coaststatus
25. Assigned altitude FL 290, transponder code (these twoitems constitute a “limited data block”)
"Note: numbers 10, 11, and 12 constitute a “full datablock”
Other symbols:
26. Navigational aid
27. Airway or jet route
28. Outline of weather returns based on primary radar.“H” represents areas of high density precipitation whichmight be thunderstorms. Radial lines indicated lowerdensity precipitation.
29. Obstruction
30. Airports
Major:Sma ll:
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4−5−3. Surveillance Radar
a. Surveillance radars are divided into two generalcategories: Airport Surveillance Radar (ASR) andAir Route Surveillance Radar (ARSR).
1. ASR is designed to provide relativelyshort−range coverage in the general vicinity of anairport and to serve as an expeditious means ofhandling terminal area traffic through observation ofprecise aircraft locations on a radarscope. The ASRcan also be used as an instrument approach aid.
2. ARSR is a long−range radar system designedprimarily to provide a display of aircraft locationsover large areas.
3. Center Radar Automated Radar TerminalSystems (ARTS) Processing (CENRAP) was devel-oped to provide an alternative to a nonradarenvironment at terminal facilities should an ASR failor malfunction. CENRAP sends aircraft radar beacontarget information to the ASR terminal facilityequipped with ARTS. Procedures used for theseparation of aircraft may increase under certainconditions when a facility is utilizing CENRAPbecause radar target information updates at a slowerrate than the normal ASR radar. Radar services forVFR aircraft are also limited during CENRAPoperations because of the additional workloadrequired to provide services to IFR aircraft.
b. Surveillance radars scan through 360 degrees ofazimuth and present target information on a radardisplay located in a tower or center. This informationis used independently or in conjunction with othernavigational aids in the control of air traffic.
4−5−4. Precision Approach Radar (PAR)
a. PAR is designed for use as a landing aid ratherthan an aid for sequencing and spacing aircraft. PARequipment may be used as a primary landing aid (SeeChapter 5, Air Traffic Procedures, for additionalinformation), or it may be used to monitor other typesof approaches. It is designed to display range,azimuth, and elevation information.
b. Two antennas are used in the PAR array, onescanning a vertical plane, and the other scanning
horizontally. Since the range is limited to 10 miles,azimuth to 20 degrees, and elevation to 7 degrees,only the final approach area is covered. Each scope isdivided into two parts. The upper half presentsaltitude and distance information, and the lower halfpresents azimuth and distance.
a. ASDE−X/ASSC is a multi−sensor surfacesurveillance system the FAA is acquiring for airportsin the United States. This system provides highresolution, short−range, clutter free surveillanceinformation about aircraft and vehicles, both movingand fixed, located on or near the surface of theairport’s runways and taxiways under all weather andvisibility conditions. The system consists of:
1. A Primary Radar System. ASDE−X/ASSC system coverage includes the airport surfaceand the airspace up to 200 feet above the surface.Typically located on the control tower or otherstrategic location on the airport, the Primary Radarantenna is able to detect and display aircraft that arenot equipped with or have malfunctioning transpond-ers.
2. Interfaces. ASDE−X/ASSC contains anautomation interface for flight identification via allautomation platforms and interfaces with theterminal radar for position information.
3. Automation. A Multi−sensor Data Proces-sor (MSDP) combines all sensor reports into a singletarget which is displayed to the air traffic controller.
4. Air Traffic Control Tower Display. A highresolution, color monitor in the control tower cabprovides controllers with a seamless picture of airportoperations on the airport surface.
b. The combination of data collected from themultiple sensors ensures that the most accurateinformation about aircraft location is received in thetower, thereby increasing surface safety andefficiency.
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4−5−8 Surveillance Systems
c. The following facilities are operational withASDE−X:
TBL 4−5−1
BWI Baltimore Washington InternationalBOS Boston Logan InternationalBDL Bradley InternationalMDW Chicago MidwayORD Chicago O’Hare InternationalCLT Charlotte Douglas InternationalDFW Dallas/Fort Worth InternationalDEN Denver InternationalDTW Detroit Metro Wayne CountyFLL Fort Lauderdale/Hollywood IntlMKE General Mitchell InternationalIAH George Bush InternationalATL Hartsfield−Jackson Atlanta IntlHNL Honolulu InternationalJFK John F. Kennedy InternationalSNA John Wayne−Orange CountyLGA LaGuardiaSTL Lambert St. Louis InternationalLAS Las Vegas McCarran InternationalLAX Los Angeles InternationalSDF Louisville InternationalMEM Memphis InternationalMIA Miami InternationalMSP Minneapolis St. Paul InternationalEWR Newark InternationalMCO Orlando InternationalPHL Philadelphia InternationalPHX Phoenix Sky Harbor InternationalDCA Ronald Reagan Washington NationalSAN San Diego InternationalSLC Salt Lake City InternationalSEA Seattle−Tacoma InternationalPVD Theodore Francis Green StateIAD Washington Dulles InternationalHOU William P. Hobby International
d. The following facilities have been projected toreceive ASSC:
TBL 4−5−2
SFO San Francisco InternationalCLE Cleveland−Hopkins InternationalMCI Kansas City InternationalCVG Cincinnati/Northern Kentucky IntlPDX Portland InternationalMSY Louis Armstrong New Orleans IntlPIT Pittsburgh InternationalANC Ted Stevens Anchorage InternationalADW Joint Base Andrews AFB
4−5−6. Traffic Information Service (TIS)
a. Introduction.
The Traffic Information Service (TIS) providesinformation to the cockpit via data link, that is similarto VFR radar traffic advisories normally receivedover voice radio. Among the first FAA−provided dataservices, TIS is intended to improve the safety andefficiency of “see and avoid” flight through anautomatic display that informs the pilot of nearbytraffic and potential conflict situations. This trafficdisplay is intended to assist the pilot in visualacquisition of these aircraft. TIS employs anenhanced capability of the terminal Mode S radarsystem, which contains the surveillance data, as wellas the data link required to “uplink” this informationto suitably−equipped aircraft (known as a TIS“client”). TIS provides estimated position, altitude,altitude trend, and ground track information for up to8 intruder aircraft within 7 NM horizontally,+3,500 and −3,000 feet vertically of the client aircraft(see FIG 4−5−4, TIS Proximity Coverage Volume).The range of a target reported at a distance greaterthan 7 NM only indicates that this target will be athreat within 34 seconds and does not display anprecise distance. TIS will alert the pilot to aircraft(under surveillance of the Mode S radar) that areestimated to be within 34 seconds of potentialcollision, regardless of distance of altitude. TISsurveillance data is derived from the same radar usedby ATC; this data is uplinked to the client aircraft oneach radar scan (nominally every 5 seconds).
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b. Requirements.
1. In order to use TIS, the client and any intruderaircraft must be equipped with the appropriatecockpit equipment and fly within the radar coverageof a Mode S radar capable of providing TIS.
Typically, this will be within 55 NM of the sitesdepicted in FIG 4−5−5, Terminal Mode S Radar Sites.ATC communication is not a requirement to receiveTIS, although it may be required by the particularairspace or flight operations in which TIS is beingused.
FIG 4−5−4TIS Proximity Coverage Volume
FIG 4−5−5Terminal Mode S Radar Sites
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FIG 4−5−6Traffic Information Service (TIS)
Avionics Block Diagram
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2. The cockpit equipment functionality requiredby a TIS client aircraft to receive the service consistsof the following (refer to FIG 4−5−6):
(a) Mode S data link transponder withaltitude encoder.
(b) Data link applications processor with TISsoftware installed.
(c) Control−display unit.
(d) Optional equipment includes a digitalheading source to correct display errors caused by“crab angle” and turning maneuvers.
NOTE−Some of the above functions will likely be combined intosingle pieces of avionics, such as (a) and (b).
3. To be visible to the TIS client, the intruderaircraft must, at a minimum, have an operatingtransponder (Mode A, C or S). All altitudeinformation provided by TIS from intruder aircraft isderived from Mode C reports, if appropriatelyequipped.
4. TIS will initially be provided by the terminalMode S systems that are paired with ASR−9 digitalprimary radars. These systems are in locations withthe greatest traffic densities, thus will provide thegreatest initial benefit. The remaining terminalMode S sensors, which are paired with ASR−7 orASR−8 analog primary radars, will provide TISpending modification or relocation of these sites. SeeFIG 4−5−5, Terminal Mode S Radar Sites, for sitelocations. There is no mechanism in place, such asNOTAMs, to provide status update on individualradar sites since TIS is a nonessential, supplementalinformation service.
The FAA also operates en route Mode S radars (notillustrated) that rotate once every 12 seconds. Thesesites will require additional development of TISbefore any possible implementation. There are noplans to implement TIS in the en route Mode S radarsat the present time.
c. Capabilities.
1. TIS provides ground−based surveillanceinformation over the Mode S data link to properlyequipped client aircraft to aid in visual acquisition ofproximate air traffic. The actual avionics capability ofeach installation will vary and the supplementalhandbook material must be consulted prior to using
TIS. A maximum of eight (8) intruder aircraft may bedisplayed; if more than eight aircraft match intruderparameters, the eight “most significant” intruders areuplinked. These “most significant” intruders areusually the ones in closest proximity and/or thegreatest threat to the TIS client.
2. TIS, through the Mode S ground sensor,provides the following data on each intruder aircraft:
(a) Relative bearing information in 6−degreeincrements.
(b) Relative range information in 1/8 NM to1 NM increments (depending on range).
(c) Relative altitude in 100−foot increments(within 1,000 feet) or 500−foot increments (from1,000−3,500 feet) if the intruder aircraft has operatingaltitude reporting capability.
(e) Altitude trend data (level within 500 fpmor climbing/descending >500 fpm) if the intruderaircraft has operating altitude reporting capability.
(f) Intruder priority as either an “trafficadvisory” or “proximate” intruder.
3. When flying from surveillance coverage ofone Mode S sensor to another, the transfer of TIS isan automatic function of the avionics system andrequires no action from the pilot.
4. There are a variety of status messages that areprovided by either the airborne system or groundequipment to alert the pilot of high priority intrudersand data link system status. These messages includethe following:
(a) Alert. Identifies a potential collisionhazard within 34 seconds. This alert may be visualand/or audible, such as a flashing display symbol ora headset tone. A target is a threat if the time to theclosest approach in vertical and horizontal coordi-nates is less than 30 seconds and the closest approachis expected to be within 500 feet vertically and0.5 nautical miles laterally.
(b) TIS Traffic. TIS traffic data is displayed.
(c) Coasting. The TIS display is more than6 seconds old. This indicates a missing uplink fromthe ground system. When the TIS display informationis more than 12 seconds old, the “No Traffic” statuswill be indicated.
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(d) No Traffic. No intruders meet proximateor alert criteria. This condition may exist when theTIS system is fully functional or may indicate“coasting” between 12 and 59 seconds old (see (c)above).
(e) TIS Unavailable. The pilot has re-quested TIS, but no ground system is available. Thiscondition will also be displayed when TIS uplinks aremissing for 60 seconds or more.
(f) TIS Disabled. The pilot has not requestedTIS or has disconnected from TIS.
(g) Good−bye. The client aircraft has flownoutside of TIS coverage.
NOTE−Depending on the avionics manufacturer implementation,it is possible that some of these messages will not be directlyavailable to the pilot.
5. Depending on avionics system design, TISmay be presented to the pilot in a variety of differentdisplays, including text and/or graphics. Voiceannunciation may also be used, either alone or incombination with a visual display. FIG 4−5−6,Traffic Information Service (TIS), Avionics BlockDiagram, shows an example of a TIS display usingsymbology similar to the Traffic Alert and CollisionAvoidance System (TCAS) installed on mostpassenger air carrier/commuter aircraft in the U.S.The small symbol in the center represents the clientaircraft and the display is oriented “track up,” with the12 o’clock position at the top. The range ringsindicate 2 and 5 NM. Each intruder is depicted by asymbol positioned at the approximate relativebearing and range from the client aircraft. Thecircular symbol near the center indicates an “alert”intruder and the diamond symbols indicate “proxi-mate” intruders.
6. The inset in the lower right corner ofFIG 4−5−6, Traffic Information Service (TIS),Avionics Block Diagram, shows a possible TIS datablock display. The following information is con-tained in this data block:
(a) The intruder, located approximatelyfour o’clock, three miles, is a “proximate” aircraftand currently not a collision threat to the clientaircraft. This is indicated by the diamond symbolused in this example.
(b) The intruder ground track diverges to theright of the client aircraft, indicated by the smallarrow.
(c) The intruder altitude is 700 feet less thanor below the client aircraft, indicated by the “−07”located under the symbol.
(d) The intruder is descending >500 fpm,indicated by the downward arrow next to the “−07”relative altitude information. The absence of thisarrow when an altitude tag is present indicates levelflight or a climb/descent rate less than 500 fpm.
NOTE−If the intruder did not have an operating altitude encoder(Mode C), the altitude and altitude trend “tags” wouldhave been omitted.
d. Limitations.
1. TIS is NOT intended to be used as a collisionavoidance system and does not relieve the pilotresponsibility to “see and avoid” other aircraft (seeparagraph 5−5−8, See and Avoid). TIS must not be foravoidance maneuvers during IMC or other timeswhen there is no visual contact with the intruderaircraft. TIS is intended only to assist in visualacquisition of other aircraft in VMC. No recom-mended avoidance maneuvers are provided for,nor authorized, as a direct result of a TIS intruderdisplay or TIS alert.
2. While TIS is a useful aid to visual trafficavoidance, it has some system limitations that mustbe fully understood to ensure proper use. Many ofthese limitations are inherent in secondary radarsurveillance. In other words, the informationprovided by TIS will be no better than that providedto ATC. Other limitations and anomalies areassociated with the TIS predictive algorithm.
(a) Intruder Display Limitations. TIS willonly display aircraft with operating transpondersinstalled. TIS relies on surveillance of the Mode Sradar, which is a “secondary surveillance” radarsimilar to the ATCRBS described in para-graph 4−5−2.
(b) TIS Client Altitude Reporting Require-ment. Altitude reporting is required by the TIS clientaircraft in order to receive TIS. If the altitude encoderis inoperative or disabled, TIS will be unavailable, asTIS requests will not be honored by the groundsystem. As such, TIS requires altitude reporting todetermine the Proximity Coverage Volume as
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indicated in FIG 4−5−4. TIS users must be alert toaltitude encoder malfunctions, as TIS has nomechanism to determine if client altitude reporting iscorrect. A failure of this nature will cause erroneousand possibly unpredictable TIS operation. If thismalfunction is suspected, confirmation of altitudereporting with ATC is suggested.
(c) Intruder Altitude Reporting. Intruderswithout altitude reporting capability will be dis-played without the accompanying altitude tag.Additionally, nonaltitude reporting intruders areassumed to be at the same altitude as the TIS client foralert computations. This helps to ensure that the pilotwill be alerted to all traffic under radar coverage, butthe actual altitude difference may be substantial.Therefore, visual acquisition may be difficult in thisinstance.
(d) Coverage Limitations. Since TIS isprovided by ground−based, secondary surveillanceradar, it is subject to all limitations of that radar. If anaircraft is not detected by the radar, it cannot bedisplayed on TIS. Examples of these limitations areas follows:
(1) TIS will typically be provided within55 NM of the radars depicted in FIG 4−5−5, TerminalMode S Radar Sites. This maximum range can varyby radar site and is always subject to “line of sight”limitations; the radar and data link signals will beblocked by obstructions, terrain, and curvature of theearth.
(2) TIS will be unavailable at low altitudesin many areas of the country, particularly inmountainous regions. Also, when flying near the“floor” of radar coverage in a particular area,intruders below the client aircraft may not be detectedby TIS.
(3) TIS will be temporarily disrupted whenflying directly over the radar site providing coverageif no adjacent site assumes the service. Aground−based radar, like a VOR or NDB, has a zenithcone, sometimes referred to as the cone of confusionor cone of silence. This is the area of ambiguitydirectly above the station where bearing informationis unreliable. The zenith cone setting for TIS is34 degrees: Any aircraft above that angle withrespect to the radar horizon will lose TIS coveragefrom that radar until it is below this 34 degree angle.The aircraft may not actually lose service in areas of
multiple radar coverage since an adjacent radar willprovide TIS. If no other TIS−capable radar isavailable, the “Good−bye” message will be receivedand TIS terminated until coverage is resumed.
(e) Intermittent Operations. TIS operationmay be intermittent during turns or other maneuver-ing, particularly if the transponder system does notinclude antenna diversity (antenna mounted on thetop and bottom of the aircraft). As in (d) above, TISis dependent on two−way, “line of sight” communica-tions between the aircraft and the Mode S radar.Whenever the structure of the client aircraft comesbetween the transponder antenna (usually located onthe underside of the aircraft) and the ground−basedradar antenna, the signal may be temporarilyinterrupted.
(f) TIS Predictive Algorithm. TIS informa-tion is collected one radar scan prior to the scanduring which the uplink occurs. Therefore, thesurveillance information is approximately 5 secondsold. In order to present the intruders in a “real time”position, TIS uses a “predictive algorithm” in itstracking software. This algorithm uses track historydata to extrapolate intruders to their expectedpositions consistent with the time of display in thecockpit. Occasionally, aircraft maneuvering willcause this algorithm to induce errors in the TISdisplay. These errors primarily affect relative bearinginformation; intruder distance and altitude willremain relatively accurate and may be used to assistin “see and avoid.” Some of the more commonexamples of these errors are as follows:
(1) When client or intruder aircraft maneu-ver excessively or abruptly, the tracking algorithmwill report incorrect horizontal position until themaneuvering aircraft stabilizes.
(2) When a rapidly closing intruder is on acourse that crosses the client at a shallow angle (eitherovertaking or head on) and either aircraft abruptlychanges course within ¼ NM, TIS will display theintruder on the opposite side of the client than itactually is.
These are relatively rare occurrences and will becorrected in a few radar scans once the course hasstabilized.
(g) Heading/Course Reference. Not all TISaircraft installations will have onboard headingreference information. In these installations, aircraftcourse reference to the TIS display is provided by the
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4−5−14 Surveillance Systems
Mode S radar. The radar only determines groundtrack information and has no indication of the clientaircraft heading. In these installations, all intruderbearing information is referenced to ground track anddoes not account for wind correction. Additionally,since ground−based radar will require several scansto determine aircraft course following a coursechange, a lag in TIS display orientation (intruderaircraft bearing) will occur. As in (f) above, intruderdistance and altitude are still usable.
(h) Closely−Spaced Intruder Errors.When operating more than 30 NM from the Mode Ssensor, TIS forces any intruder within 3/8 NM of theTIS client to appear at the same horizontal position asthe client aircraft. Without this feature, TIS coulddisplay intruders in a manner confusing to the pilot incritical situations (e.g., a closely−spaced intruder thatis actually to the right of the client may appear on theTIS display to the left). At longer distances from theradar, TIS cannot accurately determine relativebearing/distance information on intruder aircraft thatare in close proximity to the client.
Because TIS uses a ground−based, rotating radar forsurveillance information, the accuracy of TIS data isdependent on the distance from the sensor (radar)providing the service. This is much the samephenomenon as experienced with ground−basednavigational aids, such as VOR or NDB. As distancefrom the radar increases, the accuracy of surveillancedecreases. Since TIS does not inform the pilot ofdistance from the Mode S radar, the pilot must assumethat any intruder appearing at the same position as theclient aircraft may actually be up to 3/8 NM away inany direction. Consistent with the operation of TIS,an alert on the display (regardless of distance from theradar) should stimulate an outside visual scan,intruder acquisition, and traffic avoidance based onoutside reference.
e. Reports of TIS Malfunctions.
1. Users of TIS can render valuable assistance inthe early correction of malfunctions by reporting theirobservations of undesirable performance. Reportersshould identify the time of observation, location, typeand identity of aircraft, and describe the conditionobserved; the type of transponder processor, andsoftware in use can also be useful information. SinceTIS performance is monitored by maintenancepersonnel rather than ATC, it is suggested that
malfunctions be reported by radio or telephone to thenearest Flight Service Station (FSS) facility.
1. Automatic Dependent Surveillance−Broad-cast (ADS−B) is a surveillance technology deployedthroughout the NAS (see FIG 4−5−7). The ADS−Bsystem is composed of aircraft avionics and a groundinfrastructure. Onboard avionics determine theposition of the aircraft by using the GNSS andtransmit its position along with additional informa-tion about the aircraft to ground stations for use byATC and other ADS−B services. This information istransmitted at a rate of approximately once persecond. (See FIG 4−5−8 and FIG 4−5−9.)
2. In the United States, ADS−B equippedaircraft exchange information is on one of twofrequencies: 978 or 1090 MHz. The 1090 MHzfrequency is associated with Mode A, C, and Stransponder operations. 1090 MHz transponderswith integrated ADS−B functionality extend thetransponder message sets with additional ADS−Binformation. This additional information is knownas an “extended squitter” message and referred to as1090ES. ADS−B equipment operating on 978 MHzis known as the Universal Access Transceiver (UAT).
3. ADS B avionics can have the ability to bothtransmit and receive information. The transmissionof ADS−B information from an aircraft is known asADS−B Out. The receipt of ADS−B information byan aircraft is known as ADS−B In. On January 1,2020, all aircraft operating within the airspacedefined in 14 CFR Part 91 § 91.225 will be requiredto transmit the information defined in § 91.227using ADS−B Out avionics.
4. In general, operators flying at 18,000 feet andabove will require equipment which uses 1090 ES.Those that do not fly above 18,000 may use eitherUAT or 1090ES equipment. (Refer to 14 CFR 91.225and 91.227.) While the regulation will not require it,operators equipped with ADS−B In will realizeadditional benefits from ADS−B broadcast services:Traffic Information Service – Broadcast (TIS−B)(Paragraph 4−5−8) and Flight Information Service −Broadcast (FIS−B) (Paragraph 4−5−9).
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4−5−15Surveillance Systems
FIG 4−5−7ADS−B, TIS−B, and FIS−B:
Broadcast Services Architecture
b. ADS−B Certification and PerformanceRequirements.
ADS−B equipment may be certified as a surveillancesource for air traffic separation services usingADS−B Out. ADS−B equipment may also becertified for use with ADS−B In advisory servicesthat enable appropriately equipped aircraft todisplay traffic and flight information. Refer to theaircraft’s flight manual supplement or PilotOperating Handbook for the capabilities of a specificaircraft installation.
c. ADS−B Capabilities and Procedures.
1. ADS−B enables improved surveillance ser-vices, both air−to−air and air−to−ground, especiallyin areas where radar is ineffective due to terrain orwhere it is impractical or cost prohibitive. Initial NASapplications of air−to−air ADS−B are for “advisory”use only, enhancing a pilot’s visual acquisition ofother nearby equipped aircraft either when airborneor on the airport surface. Additionally, ADS−B willenable ATC and fleet operators to monitor aircraftthroughout the available ground station coveragearea.
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4−5−16 Surveillance Systems
FIG 4−5−8En Route − ADS−B/ADS−R/TIS−B/FIS−B Service Ceilings/Floors
FIG 4−5−9Terminal − ADS−B/ADS−R/TIS−B/FIS−B Service Ceilings/Floors
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4−5−17Surveillance Systems
2. An aircraft’s Flight Identification (FLT ID),also known as registration number or airline flightnumber, is transmitted by the ADS-B Out avionics.The FLT ID is comprised of a maximum of sevenalphanumeric characters and also corresponds to theaircraft identification annotated on the ATC flightplan. The FLT ID for airline and commuter aircraft isassociated with the company name and flight number(for example, AAL3342). The FLT ID is typicallyentered by the flightcrew during preflight througheither a Flight Management System (FMS) interface(Control Display Unit/CDU) or transponder controlpanel. The FLT ID for General Aviation (GA) aircraftis associated with the aircraft’s registration number.The aircraft owner can preset the FLT ID to theaircraft’s registration number (for example,N235RA), since it is a fixed value, or the pilot canenter it into the ADS-B Out system prior to flight.
ATC systems use transmitted FLT IDs to uniquelyidentify each aircraft within a given airspace andcorrelate them to a filed flight plan for the provisionof surveillance and separation services. If the FLT IDis not entered correctly, ATC automation systemsmay not associate surveillance tracks for the aircraftto its filed flight plan. Therefore, Air Traffic servicesmay be delayed or unavailable until this is corrected.Consequently, it is imperative that flightcrews andGA pilots ensure the FLT ID entry correctly matchesthe aircraft identification annotated in the filed ATCflight plan.
3. Each ADS−B aircraft is assigned a uniqueICAO address (also known as a 24−bit address) thatis broadcast by the ADS−B transmitter. The ICAOaddress is programmable at installation. Shouldmultiple aircraft broadcast the same ICAO addresswhile transiting the same ADS−B Only ServiceVolume, the ADS−B network may be unable to trackthe targets correctly. If radar reinforcement isavailable, tracking will continue. If radar isunavailable, the controller may lose target trackingentirely on one or both targets. Consequently, it isimperative that the ICAO address entry is correct.
Aircraft that is equipped with ADS−B avionics on theUAT datalink have a feature that allows it to broadcastan anonymous 24−bit ICAO address. In this mode,the UAT system creates a randomized address thatdoes not match the actual ICAO address assigned tothe aircraft. After January 1, 2020, and in the airspaceidentified in § 91.225, the UAT anonymous 24−bit
address feature may only be used when the operatorhas not filed a flight plan and is not requesting ATCservices. In the anonymity mode, the aircraft’sbeacon code must set to 1200, and depending on themanufacturer’s implementation, the aircraft’s callsign might not be transmitted. Operators should beaware that in UAT anonymous mode they will not beeligible to receive ATC separation and flightfollowing services, and will likely not benefit fromenhanced ADS−B search and rescue capabilities.
4. ADS−B systems integrated with thetransponder will automatically set the applicableemergency status when 7500, 7600, or 7700 areentered into the transponder. ADS B systems notintegrated with the transponder, or systems withoptional emergency codes, will require that theappropriate emergency code is entered through a pilotinterface. ADS−B is intended for in−flight andairport surface use. ADS−B systems should beturned “on” −− and remain “on” −− wheneveroperating in the air and moving on the airportsurface. Civil and military Mode A/C transpon-ders and ADS−B systems should be adjusted to the“on” or normal operating position as soon aspractical, unless the change to “standby” has beenaccomplished previously at the request of ATC.
d. ATC Surveillance Services using ADS−B −Procedures and Recommended Phraseology
Radar procedures, with the exceptions found in thisparagraph, are identical to those procedures pre-scribed for radar in AIM Chapter 4 and Chapter 5.
1. Preflight:
If a request for ATC services is predicated on ADS−Band such services are anticipated when either a VFRor IFR flight plan is filed, the aircraft’s FLT ID asentered in Item 7 of the ICAO flight plan (Block 2 ofFAA domestic flight plan) must be entered in theADS−B avionics.
2. Inflight:
When requesting ADS−B services while airborne,pilots should ensure that their ADS−B equipment istransmitting their aircraft’s registration number orthe approved FAA/ICAO company or organizationaldesignator, prior to contacting ATC. Aircraftequipped with a “VFR” or anonymous feature, willnot broadcast the appropriate aircraft identificationinformation and should disable the anonymousfeature before contacting ATC.
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4−5−18 Surveillance Systems
3. Aircraft with an Inoperative/MalfunctioningADS−B Transmitter:
(a) ATC will inform the flight crew when theaircraft’s ADS−B transmitter appears to be inopera-tive or malfunctioning:
PHRASEOLOGY−YOUR ADS−B TRANSMITTER APPEARS TO BEINOPERATIVE/MALFUNCTIONING. STOP ADS−BTRANSMISSIONS.
(b) ATC will inform the flight crew if itbecomes necessary to turn off the aircraft’s ADS−Btransmitter.
PHRASEOLOGY−STOP ADS−B TRANSMISSIONS.
(c) Other malfunctions and considerations:
Loss of automatic altitude reporting capabilities(encoder failure) will result in loss of ATC altitudeadvisory services.
e. ADS−B Limitations.
1. The ADS−B cockpit display of traffic is NOTintended to be used as a collision avoidance systemand does not relieve the pilot’s responsibility to “seeand avoid” other aircraft. (See paragraph 5−5−8, Seeand Avoid). ADS−B must not be used for avoidancemaneuvers during IMC or other times when there isno visual contact with the intruder aircraft. ADS−B isintended only to assist in visual acquisition of otheraircraft. No avoidance maneuvers are provided norauthorized, as a direct result of an ADS−B targetbeing displayed in the cockpit.
2. Use of ADS−B radar services is limited to theservice volume of the GBT.
NOTE−The coverage volume of GBTs are limited to line−of−sight.
f. Reports of ADS−B Malfunctions.
Users of ADS−B can provide valuable assistance inthe correction of malfunctions by reporting instancesof undesirable system performance. Since ADS-Bperformance is monitored by maintenance personnelrather than ATC, report malfunctions to the nearestFlight Service Station (FSS) facility by radio ortelephone. Reporters should identify:
1. Condition observed.
2. Date and time of observation.
3. Altitude and location of observation.
4. Type and call sign of the aircraft.
5. Type and software version of avionicssystem.
4−5−8. Traffic Information Service−Broadcast (TIS−B)
a. Introduction
TIS−B is the broadcast of ATC derived trafficinformation to ADS−B equipped (1090ES or UAT)aircraft from ground radio stations. The source of thistraffic information is derived from ground−based airtraffic surveillance sensors. TIS−B service will beavailable throughout the NAS where there are bothadequate surveillance coverage from ground sensorsand adequate broadcast coverage from ADS−Bground radio stations. The quality level of trafficinformation provided by TIS−B is dependent uponthe number and type of ground sensors available asTIS−B sources and the timeliness of the reporteddata. (See FIG 4−5−8 and FIG 4−5−9.)
b. TIS−B Requirements.
In order to receive TIS−B service, the followingconditions must exist:
1. Aircraft must be equipped with an ADS−Btransmitter/receiver or transceiver, and a cockpitdisplay of traffic information (CDTI).
2. Aircraft must fly within the coverage volumeof a compatible ground radio station that isconfigured for TIS−B uplinks. (Not all ground radiostations provide TIS−B due to a lack of radarcoverage or because a radar feed is not available).
3. Aircraft must be within the coverage of anddetected by at least one ATC radar serving the groundradio station in use.
c. TIS−B Capabilities.
1. TIS−B is intended to provide ADS−Bequipped aircraft with a more complete traffic picturein situations where not all nearby aircraft areequipped with ADS−B Out. This advisory−onlyapplication is intended to enhance a pilot’s visualacquisition of other traffic.
2. Only transponder−equipped targets(i.e., Mode A/C or Mode S transponders) aretransmitted through the ATC ground systemarchitecture. Current radar siting may result inlimited radar surveillance coverage at lower
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4−5−19Surveillance Systems
altitudes near some airports, with subsequentlylimited TIS−B service volume coverage. If there isno radar coverage in a given area, then there will beno TIS−B coverage in that area.
d. TIS−B Limitations.
1. TIS−B is NOT intended to be used as acollision avoidance system and does not relieve thepilot’s responsibility to “see and avoid” other aircraft,in accordance with 14CFR §91.113b. TIS−B mustnot be used for avoidance maneuvers during timeswhen there is no visual contact with the intruderaircraft. TIS−B is intended only to assist in the visualacquisition of other aircraft.
NOTE−No aircraft avoidance maneuvers are authorized as adirect result of a TIS−B target being displayed in thecockpit.
2. While TIS−B is a useful aid to visual trafficavoidance, its inherent system limitations must beunderstood to ensure proper use.
(a) A pilot may receive an intermittent TIS−Btarget of themselves, typically when maneuvering(e.g., climbing turns) due to the radar not trackingthe aircraft as quickly as ADS−B.
(b) The ADS−B−to−radar association pro-cess within the ground system may at times havedifficulty correlating an ADS−B report withcorresponding radar returns from the same aircraft.When this happens the pilot may see duplicate trafficsymbols (i.e., “TIS−B shadows”) on the cockpitdisplay.
(c) Updates of TIS−B traffic reports willoccur less often than ADS−B traffic updates. TIS−Bposition updates will occur approximately onceevery 3−13 seconds depending on the type of radarsystem in use within the coverage area. Incomparison, the update rate for ADS−B is nominallyonce per second.
(d) The TIS−B system only uplinks datapertaining to transponder−equipped aircraft. Aircraftwithout a transponder will not be displayed as TIS−Btraffic.
(e) There is no indication provided when anyaircraft is operating inside or outside the TIS−B
service volume, therefore it is difficult to know if oneis receiving uplinked TIS−B traffic information.
3. Pilots and operators are reminded that theairborne equipment that displays TIS−B targets is forpilot situational awareness only and is not approvedas a collision avoidance tool. Unless there is animminent emergency requiring immediate action,any deviation from an air traffic control clearance inresponse to perceived converging traffic appearingon a TIS−B display must be approved by thecontrolling ATC facility before commencing themaneuver, except as permitted under certainconditions in 14CFR §91.123. Uncoordinateddeviations may place an aircraft in close proximity toother aircraft under ATC control not seen on theairborne equipment and may result in a pilotdeviation or other incident.
e. Reports of TIS−B Malfunctions.
Users of TIS−B can provide valuable assistance in thecorrection of malfunctions by reporting instances ofundesirable system performance. Since TIS−Bperformance is monitored by maintenance personnelrather than ATC, report malfunctions to the nearestFlight Service Station (FSS) facility by radio ortelephone. Reporters should identify:
1. Condition observed.
2. Date and time of observation.
3. Altitude and location of observation.
4. Type and call sign of the aircraft.
5. Type and software version of avionicssystem.
4−5−9. Flight Information Service−Broadcast (FIS−B)
a. Introduction.
FIS−B is a ground broadcast service providedthrough the ADS−B Services network over the978 MHz UAT data link. The FAA FIS−B systemprovides pilots and flight crews of properly equippedaircraft with a cockpit display of certain aviationweather and aeronautical information. FIS−B recep-tion is line−of−sight within the service volume of theground infrastructure. (See FIG 4−5−8 andFIG 4−5−9.)
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4−5−20 Surveillance Systems
b. Weather Products.
FIS-B does not replace a preflight weather briefingfrom a source listed in Paragraph 7−1−2, FAAWeather Services, or inflight updates from an FSS orATC. FIS-B information may be used by the pilot forthe safe conduct of flight and aircraft movement;however, the information should not be the onlysource of weather or aeronautical information. Apilot should be particularly alert and understand thelimitations and quality assurance issues associatedwith individual products. This includes graphicalrepresentation of next generation weather radar(NEXRAD) imagery and Notices to Airmen(NOTAM)/temporary flight restrictions (TFR).REFERENCE−AIM, Paragraph 7−1−11 , Flight Information ServicesAdvisory Circular (AC) 00−63, “Use of Cockpit Displays of DigitalWeather and Aeronautical Information”
c. Reports of FIS−B Malfunctions.
Users of FIS−B can provide valuable assistance in thecorrection of malfunctions by reporting instances ofundesirable system performance. Since FIS−Bperformance is monitored by maintenance personnelrather than ATC, report malfunctions to the nearestFlight Service Station (FSS) facility by radio ortelephone. Reporters should identify:
1. Condition observed.
2. Date and time of observation.
3. Altitude and location of observation.
4. Type and call sign of the aircraft.
5. Type and software version of avionicssystem.
TBL 4−5−3FIS−B Basic Product Update and Transmission Intervals
1 The Update Interval is the rate at which the product data is available from the source.2 The Transmission Interval is the amount of time within which a new or updated product transmission must becompleted and the rate or repetition interval at which the product is rebroadcast.
NOTE−Details concerning the content, format, and symbols of the various data link products provided should be obtained fromthe specific avionics manufacturer.
ADS−R is a datalink translation function of theADS−B ground system required to accommodate thetwo separate operating frequencies (978 MHz and1090 ES). The ADS−B system receives the ADS−Bmessages transmitted on one frequency and ADS−Rtranslates and reformats the information forrebroadcast and use on the other frequency. Thisallows ADS−B In equipped aircraft to see nearbyADS−B Out traffic regardless of the operating link ofthe other aircraft. Aircraft operating on the sameADS−B frequency exchange information directlyand do not require the ADS−R translation function.(See FIG 4−5−8 and FIG 4−5−9.)
b. Reports of ADS−R Malfunctions.
Users of ADS−R can provide valuable assistance inthe correction of malfunctions by reporting instancesof undesirable system performance. Since ADS−Rperformance is monitored by maintenance personnelrather than ATC, report malfunctions to the nearestFlight Service Station (FSS) facility by radio ortelephone. Reporters should identify:
1. Condition observed.
2. Date and time of observation.
3. Altitude and location of observation.
4. Type and call sign of the aircraft.
5. Type and software version of avionicssystem.
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4−6−1Operational Policy/Procedures for Reduced Vertical Separation Minimum (RVSM) in theDomestic U.S., Alaska, Offshore Airspace and the San Juan FIR
Section 6. Operational Policy/Procedures for ReducedVertical Separation Minimum (RVSM) in the DomesticU.S., Alaska, Offshore Airspace and the San Juan FIR
4−6−1. Applicability and RVSM Mandate(Date/Time and Area)
a. Applicability. The policies, guidance anddirection in this section apply to RVSM operations inthe airspace over the lower 48 states, Alaska, Atlanticand Gulf of Mexico High Offshore Airspace andairspace in the San Juan FIR where VHF or UHFvoice direct controller−pilot communication (DCPC)is normally available. Policies, guidance anddirection for RVSM operations in oceanic airspacewhere VHF or UHF voice DCPC is not available andthe airspace of other countries are posted on the FAA“RVSM Documentation” web page described inParagraph 4−6−3, Aircraft and Operator ApprovalPolicy/Procedures, RVSM Monitoring and Data-bases for Aircraft and Operator Approval.
b. Mandate. At 0901 UTC on January 20, 2005,the FAA implemented RVSM between flightlevel (FL) 290−410 (inclusive) in the followingairspace: the airspace of the lower 48 states of theUnited States, Alaska, Atlantic and Gulf of MexicoHigh Offshore Airspace and the San Juan FIR. On thesame time and date, RVSM was also introduced intothe adjoining airspace of Canada and Mexico toprovide a seamless environment for aircraft travers-ing those borders. In addition, RVSM wasimplemented on the same date in the Caribbean andSouth American regions.
c. RVSM Authorization. In accordance with14 CFR Section 91.180, with only limited excep-tions, prior to operating in RVSM airspace, operatorsand aircraft must have received RVSM authorizationfrom the responsible civil aviation authority. (SeeParagraph 4−6−10, Procedures for Accommodationof Non−RVSM Aircraft.) If the operator or aircraft orboth have not been authorized for RVSM operations,the aircraft will be referred to as a “non−RVSM”aircraft. Paragraph 4−6−10 discusses ATC policiesfor accommodation of non−RVSM aircraft flown bythe Department of Defense, Air Ambulance(MEDEVAC) operators, foreign State governmentsand aircraft flown for certification and development.
Paragraph 4−6−11, Non−RVSM Aircraft RequestingClimb to and Descent from Flight Levels AboveRVSM Airspace Without Intermediate Level Off,contains policies for non−RVSM aircraft climbingand descending through RVSM airspace to/fromflight levels above RVSM airspace.
d. Benefits. RVSM enhances ATC flexibility,mitigates conflict points, enhances sector throughput,reduces controller workload and enables crossingtraffic. Operators gain fuel savings and operatingefficiency benefits by flying at more fuel efficientflight levels and on more user preferred routings.
4−6−2. Flight Level Orientation Scheme
Altitude assignments for direction of flight follow ascheme of odd altitude assignment for magneticcourses 000−179 degrees and even altitudes formagnetic courses 180−359 degrees for flights up toand including FL 410, as indicated in FIG 4−6−1.
FIG 4−6−1Flight Level Orientation Scheme
NOTE−Odd Flight Levels: Magnetic Course 000−179 DegreesEven Flight Levels: Magnetic Course 180−359 Degrees.
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4−6−2 Operational Policy/Procedures for Reduced Vertical Separation Minimum (RVSM) in theDomestic U.S., Alaska, Offshore Airspace and the San Juan FIR
4−6−3. Aircraft and Operator ApprovalPolicy/Procedures, RVSM Monitoring andDatabases for Aircraft and OperatorApproval
a. RVSM Authority. 14 CFR Section 91.180applies to RVSM operations within the U.S. 14 CFRSection 91.706 applies to RVSM operations outsidethe U.S. Both sections require that the operator obtainauthorization prior to operating in RVSM airspace.14 CFR Section 91.180 requires that, prior toconducting RVSM operations within the U.S., theoperator obtain authorization from the FAA or fromthe responsible authority, as appropriate. In addition,it requires that the operator and the operator’s aircraftcomply with the standards of 14 CFR Part 91Appendix G (Operations in RVSM Airspace).
b. Sources of Information. Advisory Circular(AC) 91−85, Authorization of Aircraft and Operatorsfor Flight in Reduced Vertical Separation Minimum(RVSM) Airspace, and the FAA RVSM website.
c. TCAS Equipage. TCAS equipage require-ments are contained in 14 CFR Sections 121.356,125.224, 129.18 and 135.189. Part 91 Appendix Gdoes not contain TCAS equipage requirementsspecific to RVSM, however, Appendix G doesrequire that aircraft equipped with TCAS II and flownin RVSM airspace be modified to incorporateTCAS II Version 7.0 or a later version.
d. Aircraft Monitoring. Operators are requiredto participate in the RVSM aircraft monitoringprogram. The “Monitoring Requirements andProcedures” section of the RVSM Documentationweb page contains policies and procedures forparticipation in the monitoring program. Ground−based and GPS−based monitoring systems areavailable for the Domestic RVSM program.Monitoring is a quality control program that enablesthe FAA and other civil aviation authorities to assessthe in−service altitude−keeping performance ofaircraft and operators.
e. Purpose of RVSM Approvals Databases.ATC does not use RVSM approvals databases todetermine whether or not a clearance can be issuedinto RVSM airspace. RVSM program managers doregularly review the operators and aircraft thatoperate in RVSM airspace to identify and investigatethose aircraft and operators flying in RVSM airspace,but not listed on the RVSM approvals databases.
f. Registration of U.S. Operators. When U.S.operators and aircraft are granted RVSM authority,the Separation Standards Group at the FAA TechnicalCenter obtains PTRS operator and aircraft informa-tion to update the FAA maintained U.S.Operator/Aircraft RVSM Approvals database. Basicdatabase operator and aircraft information can beviewed on the RVSM Documentation web page in the“RVSM Approvals” section.
4−6−4. Flight Planning into RVSM Airspace
a. Operators that do not file the correct aircraftequipment suffix on the FAA or ICAO Flight Planmay be denied clearance into RVSM airspace.Policies for the FAA Flight Plan are detailed insubparagraph c below. Policies for the ICAO FlightPlan are detailed in subparagraph d.
b. The operator will annotate the equipment blockof the FAA or ICAO Flight Plan with an aircraftequipment suffix indicating RVSM capability onlyafter the responsible civil aviation authority hasdetermined that both the operator and its aircraft areRVSM−compliant and has issued RVSM authoriza-tion to the operator.
c. General Policies for FAA Flight Plan Equip-ment Suffix. TBL 5−1−3, Aircraft Suffixes, allowsoperators to indicate that the aircraft has both RVSMand Advanced Area Navigation (RNAV) capabilitiesor has only RVSM capability.
1. The operator will annotate the equipmentblock of the FAA Flight Plan with the appropriateaircraft equipment suffix from TBL 5−1−3.
2. Operators can only file one equipment suffixin block 3 of the FAA Flight Plan. Only thisequipment suffix is displayed directly to thecontroller.
3. Aircraft with RNAV Capability. For flight inRVSM airspace, aircraft with RNAV capability, butnot Advanced RNAV capability, will file “/W”. Filing“/W” will not preclude such aircraft from filing andflying direct routes in en route airspace.
d. Policy for ICAO Flight Plan EquipmentSuffixes.
1. Operators/aircraft that are RVSM−compliantand that file ICAO flight plans will file “/W” inblock 10 (Equipment) to indicate RVSM authoriza-tion and will also file the appropriate ICAO Flight
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4−6−3Operational Policy/Procedures for Reduced Vertical Separation Minimum (RVSM) in theDomestic U.S., Alaska, Offshore Airspace and the San Juan FIR
Plan suffixes to indicate navigation and communica-tion capabilities. The equipment suffixes inTBL 5−1−3 are for use only in an FAA Flight Plan(FAA Form 7233−1).
2. Operators/aircraft that file ICAO flight plansthat include flight in Domestic U.S. RVSM airspacemust file “/W” in block 10 to indicate RVSMauthorization.
e. Importance of Flight Plan Equipment Suffixes.The operator must file the appropriate equipmentsuffix in the equipment block of the FAA Flight Plan(FAA Form 7233−1) or the ICAO Flight Plan. Theequipment suffix informs ATC:
1. Whether or not the operator and aircraft areauthorized to fly in RVSM airspace.
2. The navigation and/or transponder capabilityof the aircraft (e.g., advanced RNAV, transponderwith Mode C).
f. Significant ATC uses of the flight planequipment suffix information are:
1. To issue or deny clearance into RVSMairspace.
2. To apply a 2,000 foot vertical separationminimum in RVSM airspace to aircraft that are notauthorized for RVSM, but are in one of the limitedcategories that the FAA has agreed to accommodate.(See Paragraphs 4−6−10, Procedures for Accommo-dation of Non−RVSM Aircraft, and 4−6−11,Non−RVSM Aircraft Requesting Climb to andDescent from Flight Levels Above RVSM AirspaceWithout Intermediate Level Off, for policy on limitedoperation of unapproved aircraft in RVSM airspace).
3. To determine if the aircraft has “AdvancedRNAV” capabilities and can be cleared to flyprocedures for which that capability is required.
g. Improperly changing an aircraft equipmentsuffix and/or adding “NON-RVSM” in the NOTES orREMARKS section (Field 18) while not removingthe “W” from Field 10, will not provide air trafficcontrol with the proper visual indicator necessary todetect Non-RVSM aircraft. To ensure informationprocesses correctly for Non-RVSM aircraft, the “W”in Field 10 must be removed. Entry of information inthe NOTES or REMARKS section (Field 18) will notaffect the determination of RVSM capability andmust not be used to indicate a flight is Non-RVSM.
4−6−5. Pilot RVSM Operating Practices andProcedures
a. RVSM Mandate. If either the operator or theaircraft or both have not received RVSM authoriza-tion (non−RVSM aircraft), the pilot will neitherrequest nor accept a clearance into RVSM airspaceunless:
1. The flight is conducted by a non−RVSMDOD, MEDEVAC, certification/development orforeign State (government) aircraft in accordancewith Paragraph 4−6−10, Procedures for Accommo-dation of Non−RVSM Aircraft.
2. The pilot intends to climb to or descend fromFL 430 or above in accordance with Para-graph 4−6−11, Non−RVSM Aircraft RequestingClimb to and Descent from Flight Levels AboveRVSM Airspace Without Intermediate Level Off.
3. An emergency situation exists.
b. Basic RVSM Operating Practices andProcedures. Appendix B of AC 91−85, Authoriza-tion of Aircraft and Operators for Flight in ReducedVertical Separation Minimum Airspace, containspilot practices and procedures for RVSM. Operatorsmust incorporate Appendix B practices and proce-dures, as supplemented by the applicable paragraphsof this section, into operator training or pilotknowledge programs and operator documentscontaining RVSM operational policies.
c. Appendix B contains practices and proceduresfor flight planning, preflight procedures at theaircraft, procedures prior to RVSM airspace entry,inflight (en route) procedures, contingency proce-dures and post flight.
d. The following paragraphs either clarify orsupplement Appendix B practices and procedures.
4−6−6. Guidance on Severe Turbulenceand Mountain Wave Activity (MWA)
a. Introduction/Explanation
1. The information and practices in thisparagraph are provided to emphasize to pilots andcontrollers the importance of taking appropriateaction in RVSM airspace when aircraft experiencesevere turbulence and/or MWA that is of sufficientmagnitude to significantly affect altitude−keeping.
2. Severe Turbulence. Severe turbulencecauses large, abrupt changes in altitude and/or
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4−6−4 Operational Policy/Procedures for Reduced Vertical Separation Minimum (RVSM) in theDomestic U.S., Alaska, Offshore Airspace and the San Juan FIR
attitude usually accompanied by large variations inindicated airspeed. Aircraft may be momentarily outof control. Encounters with severe turbulence mustbe remedied immediately in any phase of flight.Severe turbulence may be associated with MWA.
3. Mountain Wave Activity (MWA)
(a) Significant MWA occurs both below andabove the floor of RVSM airspace, FL 290. MWAoften occurs in western states in the vicinity ofmountain ranges. It may occur when strong windsblow perpendicular to mountain ranges resulting inup and down or wave motions in the atmosphere.Wave action can produce altitude excursions andairspeed fluctuations accompanied by only lightturbulence. With sufficient amplitude, however,wave action can induce altitude and airspeedfluctuations accompanied by severe turbulence.MWA is difficult to forecast and can be highlylocalized and short lived.
(b) Wave activity is not necessarily limited tothe vicinity of mountain ranges. Pilots experiencingwave activity anywhere that significantly affectsaltitude−keeping can follow the guidance providedbelow.
(c) Inflight MWA Indicators (Including Tur-bulence). Indicators that the aircraft is beingsubjected to MWA are:
(1) Altitude excursions and/or airspeedfluctuations with or without associated turbulence.
(2) Pitch and trim changes required tomaintain altitude with accompanying airspeedfluctuations.
(3) Light to severe turbulence dependingon the magnitude of the MWA.
4. Priority for Controller Application ofMerging Target Procedures
(a) Explanation of Merging Target Proce-dures. As described in subparagraph c3 below, ATCwill use “merging target procedures” to mitigate theeffects of both severe turbulence and MWA. Theprocedures in subparagraph c3 have been adaptedfrom existing procedures published in FAA Order JO7110.65, Air Traffic Control, Paragraph 5−1−8,Merging Target Procedures. Paragraph 5−1−8 callsfor en route controllers to advise pilots of potentialtraffic that they perceive may fly directly above orbelow his/her aircraft at minimum vertical separa-
tion. In response, pilots are given the option ofrequesting a radar vector to ensure their radar targetwill not merge or overlap with the traffic’s radartarget.
(b) The provision of “merging target proce-dures” to mitigate the effects of severe turbulenceand/or MWA is not optional for the controller, butrather is a priority responsibility. Pilot requests forvectors for traffic avoidance when encounteringMWA or pilot reports of “Unable RVSM dueturbulence or MWA” are considered first priorityaircraft separation and sequencing responsibilities.(FAA Order JO 7110.65, Paragraph 2−1−2, DutyPriority, states that the controller’s first priority is toseparate aircraft and issue safety alerts).
(c) Explanation of the term “traffic permit-ting.” The contingency actions for MWA and severeturbulence detailed in Paragraph 4−6−9, ContingencyActions: Weather Encounters and Aircraft SystemFailures that Occur After Entry into RVSM Airspace,state that the controller will “vector aircraft to avoidmerging targets with traffic at adjacent flight levels,traffic permitting.” The term “traffic permitting” isnot intended to imply that merging target proceduresare not a priority duty. The term is intended torecognize that, as stated in FAA Order JO 7110.65,Paragraph 2−1−2, Duty Priority, there are circum-stances when the controller is required to performmore than one action and must “exercise their bestjudgment based on the facts and circumstancesknown to them” to prioritize their actions. Furtherdirection given is: “That action which is most criticalfrom a safety standpoint is performed first.”
5. TCAS Sensitivity. For both MWA andsevere turbulence encounters in RVSM airspace, anadditional concern is the sensitivity of collisionavoidance systems when one or both aircraftoperating in close proximity receive TCAS advi-sories in response to disruptions in altitude holdcapability.
b. Pre−flight tools. Sources of observed andforecast information that can help the pilot ascertainthe possibility of MWA or severe turbulence are:Forecast Winds and Temperatures Aloft (FD), AreaForecast (FA), Graphical Turbulence Guidance(GTG), SIGMETs and PIREPs.
c. Pilot Actions When Encountering Weather(e.g., Severe Turbulence or MWA)
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4−6−5Operational Policy/Procedures for Reduced Vertical Separation Minimum (RVSM) in theDomestic U.S., Alaska, Offshore Airspace and the San Juan FIR
1. Weather Encounters Inducing AltitudeDeviations of Approximately 200 feet. When thepilot experiences weather induced altitude deviationsof approximately 200 feet, the pilot will contact ATCand state “Unable RVSM Due (state reason)”(e.g., turbulence, mountain wave). See contingencyactions in paragraph 4−6−9.
2. Severe Turbulence (including that associ-ated with MWA). When pilots encounter severeturbulence, they should contact ATC and report thesituation. Until the pilot reports clear of severeturbulence, the controller will apply merging targetvectors to one or both passing aircraft to prevent theirtargets from merging:
EXAMPLE−“Yankee 123, FL 310, unable RVSM due severeturbulence.” “Yankee 123, fly heading 290; traffic twelve o’clock,10 miles, opposite direction; eastbound MD−80 atFL 320” (or the controller may issue a vector to theMD−80 traffic to avoid Yankee 123).
3. MWA. When pilots encounter MWA, theyshould contact ATC and report the magnitude andlocation of the wave activity. When a controllermakes a merging targets traffic call, the pilot mayrequest a vector to avoid flying directly over or underthe traffic. In situations where the pilot isexperiencing altitude deviations of 200 feet orgreater, the pilot will request a vector to avoid traffic.Until the pilot reports clear of MWA, the controllerwill apply merging target vectors to one or bothpassing aircraft to prevent their targets from merging:
EXAMPLE−“Yankee 123, FL 310, unable RVSM due mountain wave.” “Yankee 123, fly heading 290; traffic twelve o’clock,10 miles, opposite direction; eastbound MD−80 atFL 320” (or the controller may issue a vector to theMD−80 traffic to avoid Yankee 123).
4. FL Change or Re−route. To leave airspacewhere MWA or severe turbulence is beingencountered, the pilot may request a FL changeand/or re−route, if necessary.
4−6−7. Guidance on Wake Turbulence
a. Pilots should be aware of the potential for waketurbulence encounters in RVSM airspace. Experience
gained since 1997 has shown that such encounters inRVSM airspace are generally moderate or less inmagnitude.
b. Prior to DRVSM implementation, the FAAestablished provisions for pilots to report waketurbulence events in RVSM airspace using the NASAAviation Safety Reporting System (ASRS). A“Safety Reporting” section established on the FAARVSM Documentation web page provides contacts,forms, and reporting procedures.
c. To date, wake turbulence has not been reportedas a significant factor in DRVSM operations.European authorities also found that reports of waketurbulence encounters did not increase significantlyafter RVSM implementation (eight versus sevenreports in a ten−month period). In addition, theyfound that reported wake turbulence was generallysimilar to moderate clear air turbulence.
d. Pilot Action to Mitigate Wake TurbulenceEncounters
1. Pilots should be alert for wake turbulencewhen operating:
(a) In the vicinity of aircraft climbing ordescending through their altitude.
(b) Approximately 10−30 miles after passing1,000 feet below opposite−direction traffic.
(c) Approximately 10−30 miles behind and1,000 feet below same−direction traffic.
2. Pilots encountering or anticipating waketurbulence in DRVSM airspace have the option ofrequesting a vector, FL change, or if capable, a lateraloffset.
NOTE−1. Offsets of approximately a wing span upwind generallycan move the aircraft out of the immediate vicinity ofanother aircraft’s wake vortex.
2. In domestic U.S. airspace, pilots must request clearanceto fly a lateral offset. Strategic lateral offsets flown inoceanic airspace do not apply.
4−6−8. Pilot/Controller Phraseology
TBL 4−6−1 shows standard phraseology that pilotsand controllers will use to communicate in DRVSMoperations.
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4−6−6 Operational Policy/Procedures for Reduced Vertical Separation Minimum (RVSM) in theDomestic U.S., Alaska, Offshore Airspace and the San Juan FIR
TBL 4−6−1Pilot/Controller Phraseology
Message Phraseology
For a controller to ascertain the RVSM approval status ofan aircraft:
(call sign) confirm RVSM approved
Pilot indication that flight is RVSM approved Affirm RVSMPilot report of lack of RVSM approval (non−RVSM status).Pilot will report non−RVSM status, as follows:
a. On the initial call on any frequency in the RVSMairspace and . . ..b. In all requests for flight level changes pertaining toflight levels within the RVSM airspace and . . ..c. In all read backs to flight level clearances pertainingto flight levels within the RVSM airspace and . . ..d. In read back of flight level clearances involvingclimb and descent through RVSM airspace (FL 290 − 410).
Pilot report of one of the following after entry into RVSMairspace: all primary altimeters, automatic altitude controlsystems or altitude alerters have failed. (See Paragraph 4−6−9, Contingency Actions: WeatherEncounters and Aircraft System Failures that Occur AfterEntry into RVSM Airspace.)
NOTE−This phrase is to be used to convey both the initial indication ofRVSM aircraft system failure and on initial contact on allfrequencies in RVSM airspace until the problem ceases to existor the aircraft has exited RVSM airspace.
Unable RVSM Due Equipment
ATC denial of clearance into RVSM airspace Unable issue clearance into RVSM airspace, maintain FL*Pilot reporting inability to maintain cleared flight leveldue to weather encounter. (See Paragraph 4−6−9, Contingency Actions: WeatherEncounters and Aircraft System Failures that Occur AfterEntry into RVSM Airspace.).
*Unable RVSM due (state reason) (e.g., turbulence,mountain wave)
ATC requesting pilot to confirm that an aircraft hasregained RVSM−approved status or a pilot is ready toresume RVSM
Confirm able to resume RVSM
Pilot ready to resume RVSM after aircraft system orweather contingency
Ready to resume RVSM
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4−6−7Operational Policy/Procedures for Reduced Vertical Separation Minimum (RVSM) in theDomestic U.S., Alaska, Offshore Airspace and the San Juan FIR
4−6−9. Contingency Actions: WeatherEncounters and Aircraft System Failuresthat Occur After Entry into RVSM Airspace
TBL 4−6−2 provides pilot guidance on actions totake under certain conditions of aircraft system
failure that occur after entry into RVSM airspaceand weather encounters. It also describes theexpected ATC controller actions in these situations. Itis recognized that the pilot and controller will usejudgment to determine the action most appropriate toany given situation.
TBL 4−6−2Contingency Actions: Weather Encounters and Aircraft System Failures that Occur After Entry into RVSM
Airspace
Initial Pilot Actions in Contingency Situations
Initial pilot actions when unable to maintain flight level (FL) or unsure of aircraft altitude−keepingcapability:
#Notify ATC and request assistance as detailed below.
#Maintain cleared flight level, to the extent possible, while evaluating the situation.
#Watch for conflicting traffic both visually and by reference to TCAS, if equipped.
#Alert nearby aircraft by illuminating exterior lights (commensurate with aircraft limitations).
Severe Turbulence and/or Mountain Wave Activity (MWA) Induced Altitude Deviations of Approximately 200 feet
Pilot will: Controller will:#When experiencing severe turbulence and/orMWA induced altitude deviations ofapproximately 200 feet or greater, pilot willcontact ATC and state “Unable RVSM Due (statereason)” (e.g., turbulence, mountain wave)
#If not issued by the controller, request vectorclear of traffic at adjacent FLs
#If desired, request FL change or re−route
#Report location and magnitude of turbulence orMWA to ATC
#Vector aircraft to avoid merging target withtraffic at adjacent flight levels, traffic permitting
#Advise pilot of conflicting traffic
#Issue FL change or re−route, traffic permitting
#Issue PIREP to other aircraft
See Paragraph 4−6−6, Guidance on SevereTurbulence and Mountain Wave Activity (MWA) fordetailed guidance.
Paragraph 4−6−6 explains “traffic permitting.”
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4−6−8 Operational Policy/Procedures for Reduced Vertical Separation Minimum (RVSM) in theDomestic U.S., Alaska, Offshore Airspace and the San Juan FIR
Mountain Wave Activity (MWA) Encounters − General
Pilot actions: Controller actions:#Contact ATC and report experiencing MWA
#If so desired, pilot may request a FL change orre−route
#Report location and magnitude of MWA to ATC
#Advise pilot of conflicting traffic at adjacent FL
#If pilot requests, vector aircraft to avoid mergingtarget with traffic at adjacent RVSM flight levels,traffic permitting
#Issue FL change or re−route, traffic permitting
#Issue PIREP to other aircraft
See paragraph 4−6−6 for guidance on MWA. Paragraph 4−6−6 explains “traffic permitting.”NOTE−MWA encounters do not necessarily result in altitude deviations on the order of 200 feet. The guidance below isintended to address less significant MWA encounters.
Wake Turbulence Encounters
Pilot should: Controller should:#Contact ATC and request vector, FL change or,if capable, a lateral offset
#Issue vector, FL change or lateral offsetclearance, traffic permitting
See Paragraph 4−6−7, Guidance on WakeTurbulence.
Paragraph 4−6−6 explains “traffic permitting.”
“Unable RVSM Due Equipment”Failure of Automatic Altitude Control System, Altitude Alerter or All Primary Altimeters
Pilot will: Controller will:#Contact ATC and state “Unable RVSM DueEquipment”
#Request clearance out of RVSM airspace unlessoperational situation dictates otherwise
#Clear aircraft out of RVSM airspace unlessoperational situation dictates otherwise
One Primary Altimeter Remains Operational
Pilot will: Controller will:#Cross check stand−by altimeter
#Notify ATC of operation with single primaryaltimeter
#If unable to confirm primary altimeter accuracy,follow actions for failure of all primary altimeters
#Acknowledge operation with single primaryaltimeter
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4−6−9Operational Policy/Procedures for Reduced Vertical Separation Minimum (RVSM) in theDomestic U.S., Alaska, Offshore Airspace and the San Juan FIR
Transponder Failure
Pilot will: Controller will:#Contact ATC and request authority to continueto operate at cleared flight level
#Comply with revised ATC clearance, if issued
#Consider request to continue to operate atcleared flight level
#Issue revised clearance, if necessary
NOTE−14 CFR Section 91.215 (ATC transponder and altitudereporting equipment and use) regulates operation with thetransponder inoperative.
4−6−10. Procedures for Accommodation ofNon−RVSM Aircraft
a. General Policies for Accommodation ofNon−RVSM Aircraft
1. The RVSM mandate calls for only RVSMauthorized aircraft/operators to fly in designatedRVSM airspace with limited exceptions. The policiesdetailed below are intended exclusively for use byaircraft that the FAA has agreed to accommodate.They are not intended to provide other operators ameans to circumvent the normal RVSM approvalprocess.
2. If either the operator or aircraft or both havenot been authorized to conduct RVSM operations, theaircraft will be referred to as a “non−RVSM” aircraft.14 CFR Section 91.180 and Part 91 Appendix Genable the FAA to authorize a deviation to operate anon−RVSM aircraft in RVSM airspace.
3. Non−RVSM aircraft flights will be handledon a workload permitting basis. The verticalseparation standard applied between aircraft notapproved for RVSM and all other aircraft must be2,000 feet.
4. Required Pilot Calls. The pilot of non−RVSM aircraft will inform the controller of the lackof RVSM approval in accordance with the directionprovided in Paragraph 4−6−8, Pilot/ControllerPhraseology.
b. Categories of Non−RVSM Aircraft that maybe Accommodated
Subject to FAA approval and clearance, the followingcategories of non−RVSM aircraft may operate indomestic U.S. RVSM airspace provided they have anoperational transponder.
1. Department of Defense (DOD) aircraft.
2. Flights conducted for aircraft certificationand development purposes.
3. Active air ambulance flights utilizing a“MEDEVAC” call sign.
4. Aircraft climbing/descending throughRVSM flight levels (without intermediate level off)to/from FLs above RVSM airspace (Policies for theseflights are detailed in Paragraph 4−6−11, Non−RVSMAircraft Requesting Climb to and Descent fromFlight Levels Above RVSM Airspace WithoutIntermediate Level Off.
5. Foreign State (government) aircraft.
c. Methods for operators of non−RVSM aircraft torequest access to RVSM Airspace. Operators may:
1. LOA/MOU. Enter into a Letter of Agree-ment (LOA)/Memorandum of Understanding(MOU) with the RVSM facility (the Air Trafficfacility that provides air traffic services in RVSMairspace). Operators must comply with LOA/MOU.
2. File−and−Fly. File a flight plan to notify theFAA of their intention to request access to RVSMairspace.NOTE−Priority for access to RVSM airspace will be afforded toRVSM compliant aircraft, then File−and−Fly flights.
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4−6−10 Operational Policy/Procedures for Reduced Vertical Separation Minimum (RVSM) in theDomestic U.S., Alaska, Offshore Airspace and the San Juan FIR
4−6−11. Non−RVSM Aircraft RequestingClimb to and Descent from Flight LevelsAbove RVSM Airspace WithoutIntermediate Level Off
a. File−and−Fly. Operators of Non−RVSM air-craft climbing to and descending from RVSM flightlevels should just file a flight plan.
b. Non−RVSM aircraft climbing to and descend-ing from flight levels above RVSM airspace will behandled on a workload permitting basis. The verticalseparation standard applied in RVSM airspacebetween non−RVSM aircraft and all other aircraftmust be 2,000 feet.
c. Non−RVSM aircraft climbing to/descendingfrom RVSM airspace can only be considered foraccommodation provided:
1. Aircraft is capable of a continuous climb/de-scent and does not need to level off at an intermediatealtitude for any operational considerations and
2. Aircraft is capable of climb/descent at thenormal rate for the aircraft.
d. Required Pilot Calls. The pilot of non−RVSMaircraft will inform the controller of the lack ofRVSM approval in accordance with the directionprovided in Paragraph 4−6−8, Pilot/ControllerPhraseology.
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4−7−1Operational Policy/Procedures for the Gulf of Mexico 50 NM Lateral Separation Initiative
Section 7. Operational Policy/Procedures for the Gulf ofMexico 50 NM Lateral Separation Initiative
4−7−1. Introduction and General Policies
a. Air traffic control (ATC) may apply 50 nauticalmile (NM) lateral separation (i.e., lateral spacing)between airplanes authorized for Required Naviga-tion Performance (RNP) 10 or RNP 4 operating in theGulf of Mexico. 50 NM lateral separation may beapplied in the following airspace:
1. Houston Oceanic Control Area (CTA)/FlightInformation Region (FIR).
2. Gulf of Mexico portion of the Miami OceanicCTA/FIR.
3. Monterrey CTA.
4. Merida High CTA within the MexicoFIR/UTA.
b. Within the Gulf of Mexico airspace describedabove, pairs of airplanes whose flight plans indicateapproval for PBN and either RNP 10 or RNP 4 maybe spaced by ATC at lateral intervals of 50 NM. ATCwill space any airplane without RNP 10 or RNP 4capability such that at least 90 NM lateral separationis maintained with other airplanes in the MiamiOceanic CTA, and at least 100 NM separation ismaintained in the Houston, Monterrey, and MeridaCTAs.
c. The reduced lateral separation allows moreairplanes to fly on optimum routes/altitudes over theGulf of Mexico.
d. 50 NM lateral separation is not applied onroutes defined by ground navigation aids or on GulfRNAV Routes Q100, Q102, or Q105.
e. Information useful for flight planning andoperations over the Gulf of Mexico under this 50 NMlateral separation policy, as well as information onhow to obtain RNP 10 or RNP 4 authorization, can befound in the West Atlantic Route System, Gulf ofMexico, and Caribbean Resource Guide for U.S.Operators located at:www.faa.gov/about/office_org/headquarters_offices/avs /off ices /afx /afs /afs400/afs470/media/WATRS.pdf
f. Pilots should use Strategic Lateral OffsetProcedures (SLOP) in the course of regularoperations within the Gulf of Mexico CTAs. SLOPprocedures and limitations are published in the U.S.Aeronautical Information Publication (AIP), ENRSection 7.1, General Procedures; Advisory Circular(AC) 91−70, Oceanic and Remote ContinentalAirspace Operations; and ICAO Document 4444,Procedures for Air Navigation Services – Air TrafficManagement.
4−7−2. Accommodating Non−RNP 10Aircraft
a. Operators not authorized for RNP 10 or RNP 4may still file for any route and altitude within the Gulfof Mexico CTAs. However, clearance on theoperator’s preferred route and/or altitude will beprovided as traffic allows for 90 or 100 NM lateralseparation between the non−RNP 10 aircraft and anyothers. Priority will be given to RNP 10 or RNP 4aircraft.
b. Operators of aircraft not authorized RNP 10 orRNP 4 must include the annotation “RMK/NON-RNP10” in Item 18 of their ATC flight plan.
c. Pilots of non−RNP 10 aircraft are to remindATC of their RNP status; i.e., report “negativeRNP 10” upon initial contact with ATC in each GulfCTA.
d. Operators will likely benefit from the effortthey invest to obtain RNP 10 or RNP 4 authorization,provided they are flying aircraft equipped to meetRNP 10 or RNP 4 standards.
4−7−3. Obtaining RNP 10 or RNP 4Operational Authorization
a. For U.S. operators, AC 90−105, ApprovalGuidance for RNP Operations and BarometricVertical Navigation in the U.S. National AirspaceSystem and in Oceanic and Remote ContinentalAirspace, provides the aircraft and operatorqualification criteria for RNP 10 or RNP 4authorizations. FAA personnel at flight standardsdistrict offices (FSDO) and certificate managementoffices (CMO) will use the guidance contained in
3/29/18 AIM
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4−7−2 Operational Policy/Procedures for the Gulf of Mexico 50 NM Lateral Separation Initiative
AC 90−105 to evaluate an operator’s application forRNP 10 or RNP 4 authorization. Authorization toconduct RNP operations in oceanic airspace isprovided to all U.S. operators through issuance ofOperations Specification (OpSpec), ManagementSpecification (MSpec), or Letter of Authorization(LOA) B036, as applicable to the nature of theoperation; for example, Part 121, Part 91, etc.Operators may wish to review FAA Order 8900.1,Flight Standards Information Management System,volume 3, chapter 18, section 4, to understand thespecific criteria for issuing OpSpec, MSpec, and/orLOA B036.
b. The operator’s RNP 10 or RNP 4 authorizationshould include any equipment requirements andRNP 10 time limits (if operating solely inertial−based navigation systems), which must be observedwhen conducting RNP operations. RNP 4 requirestighter navigation and track maintenance accuracythan RNP 10.
4−7−4. Authority for Operations with aSingle Long−Range Navigation System
Operators may be authorized to take advantage of50 NM lateral separation in the Gulf of Mexico CTAswhen equipped with only a single long−rangenavigation system. RNP 10 with a single long−rangenavigation system is authorized via OpSpec, MSpec,or LOA B054. Operators should contact their FSDOor CMO to obtain information on the specificrequirements for obtaining B054. Volume 3, chapter18, section 4 of FAA Order 8900.1 provides thequalification criteria to be used by FAA aviationsafety inspectors in issuing B054.
4−7−5. Flight Plan Requirements
a. In order for an operator with RNP 10 or RNP 4authorization to obtain 50 NM lateral separation in
the Gulf of Mexico CTAs, and therefore obtainpreferred routing available to RNP authorizedaircraft, the international flight plan form (FAA7233−4) must be annotated as follows:
1. Item 10a (Equipment) must include the letter“R.”
2. Item 18 must include either “PBN/A1” forRNP 10 authorization or “PBN/L1” for RNP 4authorization.
b. Indication of RNP 4 authorization implies theaircraft and pilots are also authorized RNP 10.
c. Chapter 5, section 1, of this manual includesinformation on all flight plan codes. RNP 10 has thesame meaning and application as RNAV 10. Theyshare the same code.
4−7−6. Contingency Procedures
Pilots operating under reduced lateral separationmust be particularly familiar with, and prepared torapidly implement, the standard contingency proce-dures specifically written for operations whenoutside ATC surveillance and direct VHF communi-cations (for example, the oceanic environment).Specific procedures have been developed for weatherdeviations. Operators should ensure all flight crewsoperating in this type of environment have beenprovided the standard contingency procedures in areadily accessible format. The margin for error whenoperating at reduced separation mandates correct andexpeditious application of the standard contingencyprocedures. These internationally accepted proce-dures are published in ICAO Document 4444,chapter 15. The procedures are also reprinted in theU.S. Aeronautical Information Publication (AIP),En Route (ENR) Section 7.3, Special Procedures forIn−flight Contingencies in Oceanic Airspace; andAC 91−70.
