A & P Mechanic: see Aircraft & Powerplant Mechanic Abeam: An aircraft is ʺabeamʺ a fix, point, or object when that fix, point, or object is approximately 90 degrees to the right or left of the aircraft track. Abeam indicates a general position rather than a precise point. ABO: See Aviators Breathing Oxygen Abort: To terminate a preplanned aircraft maneuver; i.e., an aborted takeoff. Above Ground Fuel Storage Facility: A Fuel Storage Facility (system) whereby the fuel storage tanks are located above ground level. Above Ground Level: The height of an aircraft above ground level; also known as absolute altitude. May be determined by subtracting the elevation of the ground from the flight altitude above mean sea level. ʺAcknowledgeʺ: Let me know that you have received and understood my message. Acrobatic Flight: An intentional maneuver involving an abrupt change in an aircraftʹs altitude, an abnormal attitude, abnormal acceleration not necessary for normal flight. ʺAdvise Intentionsʺ: Tell me what you plan to do. Advisory: Advice and information provided by a facility to assist pilots in the safe conduct of flight and aircraft movement. AD: see Airworthiness Directive. AD Oil: see Ashless Dispersant Oil . Advisory Frequency: The appropriate frequency to be used for airport advisory service. Advisory Service: Advice and information provided by a facility to assist pilots in the safe conduct of flight and aircraft movement. Aerial Refueling: A procedure used by the military to transfer fuel from one aircraft to another during flight. Aeronautical Chart: A map used in air navigation containing all or part of the following: Topographical features, hazards and
obstructions, navigation aids, navigation routes, designated airspace, and airports. Commonly used aeronautical charts are: 1. Sectional Charts: Designed for visual navigation of slow or medium speed aircraft. 2. VFR Terminal Area Charts: Depict Class B airspace that provides for control or segregation of all the aircraft within the Class B airspace. 3. World Aeronautical Charts (WAC): Provide a standard series of aeronautical charts covering land areas of the world at a size and scale convenient for navigation by moderate speed aircraft. 4. En Route Low Altitude Charts: Provide aeronautical information for en route instrument navigation (IFR) in the low altitude stratum. 5. En Route High Altitude Charts: Provide aeronautical information for En route instrument navigation (IFR) in the high altitude stratum. AFD: see Airport Facility Directory ʺAffirmativeʺ: Yes. Aft: Toward the rear of the aircraft. AGL: see Above Ground Level. Aileron: A primary flight control surface mounted on the trailing edge of the airplane wing, near the tip. Air Brake: Any device primarily used to increase the drag of an aircraft. Air Carrier Operations: Arrivals and departures of air carriers certificated in accordance with FAR Part 121 and 127. Aircraft & Powerplant Mechanic: An aviation mechanic who is licensed by the FAA and holds combined ratings of Airframe (A) and Powerplant (P). The A&P Mechanic services, repairs, and overhauls aircraft and aircraft engines to insure airworthiness. Air Route Traffic Control Center: A facility established to provide air traffic control service to aircraft operating on an IFR flight plan within controlled airspace and principally during the en route phase of flight. When equipment capabilities and controller workload permit, certain advisory services may be provided to VFR aircraft. Air Taxi Operator: An air carrier certificated in accordance with FAR Part 135 and authorized to provide, on demand, public
transportation of persons and property by aircraft. Generally operates small aircraft ʺfor hireʺ for specific trips. Air Traffic: Aircraft operating in the air or on an airport surface, exclusive of loading ramps and parking areas. Air Traffic Control: A service operated by appropriate authority to promote the safe, orderly and expeditious flow of air traffic. Aircraft: A machine that can derive support from the atmosphere from the reaction of the air other than the reaction of the air against the earthʹs surface. Aircraft Classes: For the purposes of Wake Turbulence Separation Minima, ATC classifies aircraft as Heavy, Large, and Small as follows: (1) Heavy ‐ Aircraft capable of takeoff weights of 300,000 pounds (136,078 kg) or more whether or not they are operating at this weight during a particular phase of flight. (2) Large ‐ Aircraft of more than 12,500 pounds (5,670 kg), maximum certificated takeoff weight, up to 300,00 (136,078 kg) pounds. (3) Small ‐ Aircraft of 12,500 pounds (5,670 kg) or less maximum certificated takeoff weight. Aircraft Dispatch: The control and management of aircraft operations including; aircraft scheduling, weight and balance computation, route of flight planning, and weather data gathering. Aircraft Operations: The airborne movement of aircraft in controlled or uncontrolled airport terminal areas, and counts at en route fixes or other points where aircraft movements can be counted. There are two types of operations: local and itinerant. (1) LOCAL OPERATIONS are performed by aircraft that: (a) operate in the local traffic pattern or within sight of the airport; (b) are known to be departing for or arriving from flights in local practice areas located within a 20‐mile radius of the airport; execute simulated instrument approaches or low passes at the airport. (2) ITINERANT OPERATIONS are all aircraft operations other than local operations. Aircraft Rescue and Fire Fighting: Airport Fire Fighters specializing in aircraft fire and rescue techniques. Airfoil: Any surface, such as an aircraft wing or helicopter Rotor, designed to obtain a useful reaction, such as lift, from air passing over it. Airframe: The structure of an aircraft that does not include the powerplant. This would include the wings, fuselage, and tail Airmanʹs Meteorological Information: In‐flight weather advisories issued only to amend the area forecast concerning weather phenomena which are of operational interest to all
aircraft and potentially hazardous to aircraft having limited capability because of lack of equipment, instrumentation, or pilot qualifications. Airmets cover moderate icing, moderate turbulence, sustained winds of 30 or more at the surface, widespread areas of ceilings less than 1,000 feet and\or visibility less than 3 miles, and extensive mountain obscurement. AIRMET: see Airmanʹs Meteorological Information Airplane: An engine driven fixed wing aircraft that is heavier than the air, and is supported in flight by the dynamic reaction of the air against its wings. Airport: An area on land or water that is used or intended to be used for the landing and takeoff of aircraft and includes its buildings and facilities, if any. Airport Advisory Service: A service provided by flight service stations at airports not served by a control tower. This service provides information to arriving and departing aircraft concerning wind direction/speed, favored runway, altimeter setting, pertinent known traffic/field conditions, airport taxi routes, traffic patterns, and authorized instrument approach procedures. Airport Elevation: The highest point of an airportʹs usable runways measured in feet from mean sea level. Airport Facility Directory: A publication designed as a pilotʹs operational manual containing all airports, seaplane bases, and heliports open to the public including communications data, navigational facilities, and certain special notices and procedures. Air Operations Area: The area used or intended to be used for the landing, takeoff or surface maneuvering of aircraft. Airport Rotating Beacon: A visual navaid operated at many airports. At civil airports, alternating white and green flashes indicate the location of the airport. At military airports, the beacons flash alternately white and green but a re differentiated from civil beacons by dual‐peaked (two quick) white flashes between the green flashes. Airport Surveillance Radar: Approach control radar used to detect and display an aircraftʹs position in the terminal area. ASR provides range and azimuth information but does not provide elevation data. Airport Traffic Control Tower: See Tower Airspeed: The speed of an aircraft relative to its surrounding air mass. The unqualified term ʺairspeedʺ means one of the following: 1. Indicated Airspeed – The speed shown on the aircraft airspeed indicator. This is the speed used in pilot/controller
communications; it is referred to under the general term ʺairspeed.ʺ 2. True Airspeed ‐ The airspeed of an aircraft relative to undisturbed air. Used primarily in flight planning and the enroute portion of flight. When used in pilot/controller communications, it is referred to as ʺtrue airspeedʺ and not shortened to ʺairspeed.ʺ This is the ʺIndicated Airspeedʺ corrected for error due to air density (temperature and altitude). Airstart Unit (Ground): A mobile unit housing a turbine engine or other device used to generate high pressure air to rotate the turbine engine blades and start larger aircraft. Airworthiness Certificate: A certificate issued by the Federal Aviation Administration to aircraft that meet the minimum standards for airworthiness as specified in the appropriate part of the Federal Aviation Regulations. Airworthiness Directive: During the life of an aircraft, the manufacturer will sometimes find defects in the aircraft that make it unsafe for flight. When this occurs, the FAA issues what is called an AD. ADʹs require the aircraft owner/operator to replace or repair the defect before the aircraft can continue to be operated. All‐Cargo Carrier: An air carrier certificated in accordance with FAR Part 121to provide scheduled air freight, express, and mail transportation over specified routes, as well as to conduct nonscheduled operations that may include passengers. Alternate Airport: An airport at which an aircraft may land if a landing at the intended airport becomes inadvisable. Altimeter: An instrument for measuring height above a reference datum. Specifically an instrument, similar to an aneroid barometer, that utilizes the change of atmospheric pressure with altitude to indicate the approximate elevation above a given point or plane used as a reference. Altimeter Setting: The barometric pressure reading used to adjust a pressure altimeter for variations in existing atmospheric pressure. This setting is calibrated based upon a standard altimeter setting of (29.92ʺHg.) Altitude: The height of a level, point, or object measured in feet above ground level (agl) or from mean sea level (msl). 1. MSL‐ Altitude expressed in feet measured from mean sea level. 2. AGL ‐ expressed in feet measured above ground level. 3. Indicated ‐ The altitude as shown by a pressure altimeter uncorrected for instrument error or variation from standard atmospheric conditions. Ambient temperature: The air temperature surrounding a specific area.
American Petroleum Institute: A national society that has developed standards for aviation fuel, and aviation fuel handling equipment and procedures. (http://www.api.org/) American Society for Testing and Materials: http://www.astm.org/ Amperage: A value that expresses current; a measure of the rate of electrical flow. For example; fuel flow is measured in gallons per minute. The ʺgallonʺ is the quantity, and the ʺgallons per minuteʺ is the rate of flow. Using this example, ampere is the rate of flow. Anti‐Collision Light: A high intensity, flashing or condenser discharge light or group of lights mounted on an aircraft to allow it to be seen more easily. Anti‐icing: Measures used to prevent ice formation on aircraft. AOA: see Airport Operations Area API: see American Petroleum Institute API Degrees: Units for fuel density measurement. API Gravity: A specific test method for determining the density of fuel. It is an arbitrary scale expressing the gravity or density of liquid petroleum products. The measuring scale is calibrated in terms of degrees API. It may be calculated in terms of the following formula: ºAPI = (141.5 ÷ Specific Gravity @ 60ºF) ‐ 131.5 Approach: The segment of an airplane flight just preceding, and in preparation for, a landing. Apron: A defined area, outdoors and normally paved, on an airport or heliport intended to accommodate aircraft purposes of loading or unloading passengers or cargo, refueling, defueling, servicing, parking, securing, or maintenance. With regard to seaplanes, a ramp may be used for access to or from the water. APU: see Auxiliary Power Unit ARTCC: see Air Route Traffic Control Center ARFF: see Aircraft Rescue and FireFighting Ashless Dispersant Oil: A form of mineral oil used as a lubricant for aircraft reciprocating engines, which contains additives that keep the contaminants, that form in the oil, dispersed throughout the oil so that they will not join together and clog the oil filters. ASTM: see American Society for Testing and Materials. ATC: see Air Traffic Control
ATIS: see Automatic Terminal Information Service Attitude: The relationship of an aircraft and a fixed reference; normally used with respect to the horizon of the earth. Auto‐Ignition Temperature: The temperature at which a mixture of flammable vapor and air will ignite from contact with a hot surface such as a muffler, exhaust pipe, turbine engine, brake pads, etc. without a flame or spark. For jet fuel, the temperature is approximately 475ºF (246ºC) and for Avgas it is approximately 840ºF (449ºC). These are relatively low temperatures when one considers the exhaust pipe of a common engine is normally about 950ºF(510Cº) when the engine is running, and it takes some turbine engines 20‐25 minutes from the time the fan blades stop rotating after shut‐down to the time the blades have cooled below 475ºF (246ºC). Automatic Shutoff (aircraft): Fuel level sensing devices within the aircraftʹs various tanks that automatically close the valve to the individual tank thus stopping the flow of fuel when a tank has reached its maximum or predetermined level. Automatic Terminal Information Service: The continuous broadcast of recorded non‐control information in selected terminal areas. Its purpose is to improve controller effectiveness and to relieve frequency congestion by automating the repetitive transmission of essential by routine information; e.g., ʺLos Angeles information Alpha. One‐three‐ zero Coordinated Universal Time. Weather, measured ceiling two thousand overcast, visibility three, haze, smoke, temperature seven‐one, dew point five‐seven, wind two‐five‐zero at five, altimeter two niner, niner six. ILS Runway Two‐five Left approach in use, Runway Two‐five Right closed ‐‐ advise you have Alpha.ʺ Auxiliary Fuel Tanks: Those fuel tanks that are designated as the secondary supply of fuel for the engines, and are utilized for extended range flight operations. Auxiliary Power Unit: A self contained power unit on an aircraft providing electrical/pneumatic power to aircraft systems during ground operations. AVGAS: see Aviation Gasoline Aviation Gasoline (AVGAS): A gasoline manufactured specifically for use as aviation fuel in reciprocating engines. Must not be contaminated with ordinary motor gasoline nor motor gasoline used in its place. As an example, AVGAS 100/130 normally contains less than 4.0 ml/gal of tetraethyl lead and is colored green. AVGAS 100LL is a low lead AVGAS 100 that contains less than 2.0 ml/gal of tetraethyl lead and is colored blue. AVGAS is considered a Flammable, Class IB (NFPA 30). These products are manufactured to meet Specification ASTM D910, UK Def Stan 91‐90 and/or other local government or airline specifications.
Aviation Safety Reporting Program: A voluntary reporting program that invites pilots, controllers, maintenance people, and others directly involved in aviation to contribute to the FAAʹs efforts to promote safety by reporting actual or potential safety discrepancies or deficiencies. NASA handles receipt, processing, and analysis of raw data under its Aviation Safety Reporting System. Aviators Breathing Oxygen: Oxygen containing 99.5% pure oxygen, and not more than .005 milligrams of water per liter. Balanced Fuel Loading: The loading of fuel on board an aircraft in a manner so that the fuel is equally distributed to both the left and right wings or in such a way as to assure a proper aircraft center of gravity and balance. Beacon: A light, or group of lights, or electronic source that emits a distinctive signal used for the determination of bearings, courses, or location. Below Ground Fuel Storage Facility: A Fuel Storage Facility (system) whereby all fuel storage tanks are located below ground level. Below Minimums: Weather conditions below the minimum prescribed by regulation for the particular action involved; e.g., landing minimums, takeoff minimums. Biplane: An airplane with two main supporting surfaces (wings) placed one above the other. Blast Fence: A barrier that is used to divert or dissipate jet or propeller blast. Bleed Air: Compressed air from the engine compressor directed into the cabin pressurization system, or to drive others services. Blind Spot: An area from which radio transmissions and/or radar echoes cannot be received. The term is also used to describe portions of the airport not visible from the control tower. Block To Block Time: The period between the time the aircraft first commences to move with the intention of flight to the time it finally comes to a stop after the flight. Blue Ice: Lavatory system water that has leaked out of the aircraft and freezes when the aircraft is airborne at cold temperatures. This ice may break off and cause possible damage to the aircraft and engines in addition to people and personnel on the ground. Bonding: A method of ensuring that the same electrical potential exists between separate units (i.e., aircraft/refueler; filter/bucket; transport truck/receiving facility; etc.) by connecting the units with conductive wire or cable.
Bonding Plug: A single plug connected to the end of a conductive wire or cable that may be connected to an over wing nozzle and/or a single point nozzle and is inserted into a designated area near the refueling filler prior to nozzle insertion/connection. Bottom Loading: The loading of fuel into an aircraft refueler tank through a coupler connection on the lower portion of the refueler tank. The refill process utilizes pressure to move the fuel into the tank. Braking Action: A report of conditions on the airport movement area providing a pilot with a degree/quality of braking that might be expected. Braking action is reported in terms of good, fair, poor and nil. Braking Action Advisories: When tower controllers have received runway braking action reports which include the terms ʺpoorʺ or ʺnilʺ, or whenever weather conditions are conducive to deteriorating or rapidly changing runway braking conditions, the tower will include on the ATIS broadcast the statement, ʺBraking action advisories are in effect.ʺ During the time braking action advisories are in effect, ATC will issue the latest braking action report for the runway in use to each arriving and departing aircraft. British Standards Institution: A British national society responsible for establishing standards for products and equipment. British Thermal Unit: Refers to the quantity of heat required to raise by 1ºF, the temperature of water at its maximum density (39.2ºF). BSI: see British Standards Institution. BTU: see British Thermal Unit. Bulkhead (aircraft): A structural division of the compartments within the fuselage designed to strengthen the aircraft and act as a wall. Business Transportation: Any use of an aircraft, not for compensation or hire, by an individual for transportation required by the business in which the individual is engaged. Cabin (aircraft): The component or section within the fuselage utilized for the carriage of passengers. Call Sign: Letters, numbers or words used for aircraft identification purposes. Canard: Small wings located forward of the main wings. Acting like a horizontal stabilizer, it provides longitudinal stability and may control the pitch attitude of the aircraft.
Canopy: A transparent enclosure, similar in shape to that of a clamshell, covering the cockpit which protects the pilots from the wind while also offering improved visibility. CAT: see Clear Air Turbulence Cathodic Protection: An electrical or electro‐chemical method of protecting pipelines, storage tanks, and other fixed equipment from external corrosion. Ceiling: The height above the earthʹs surface of the lowest layer of clouds or obscuring phenomena that is reported as ʺbrokenʺ, ʺovercastʺ or ʺobscurationʺ, and not classified as ʺthinʺ or partial. Centerline: A real or imaginary line down the middle of the runway. Centerline Thrust: The thrust produced by a twin engine aircraft that has its engines arranged ʺin‐lineʺ (front and back) along the center axis of the aircraft. An example would be the Cessna‐337, ʺSkymaster.ʺ Certificate Management Offices: Certificate Management Offices specialize in the certification, surveillance and inspection of major air carriers and Flight Safety International’s part 142 Training Centers.. CH: see Compass Heading Chock: A triangular block of metal, rubber or wood placed in front of and behind the tires of an aircraft to keep the aircraft from rolling. Clay Filter: see filter types. Clear Air Turbulence: Turbulence encountered in air where no clouds are present. This term is commonly applied to high level turbulence associated with wind shear. CAT is often encountered in the vicinity of the jet stream. Clear and bright: A condition in which the fuel contains no visible water drops or particulates, and is free of haze or cloudiness. Climb‐Out: That portion of flight operation between takeoff and the initial cruising altitude. Closed Runway: A runway that is unusable for aircraft operations. (Only the airport management/military operations office can close a runway.) CMO: see Certificate Management Offices Coalescence: The property of a filter cartridge to bring together very fine droplets of free and entrained water to form large droplets which are heavy enough to fall to the bottom of the filter separator vessel.
Coalescer Element: A device that removes solid particles and coalesces free or entrained water from fuel and is the first stage cartridge in the filter separator vessel. It is upstream of the separator cartridge. Cockpit: see Flight Deck Cockpit Voice Recorder: A tape recording system fitted to an aircraft which records voice communication between the flight crew. Combustible: Refers to any liquid with a Flash Point above 140ºF (60ºC). Commercial Air Carriers: An air carrier certificated in accordance with FAR Part 121or 127 to conduct scheduled or charter services as a secondary operation. Commuter Air Carrier: An air carrier certificated in accordance with FAR Part 135 or 121 that operates aircraft with a maximum of 60 seats, and that provides at least five scheduled round trips per week between two or more points, or that carries mail. Commuter/Air Taxi Operations: Arrivals and Departures of air carriers certificated in accordance with FAR Part 135. Compass Heading: Heading flown by reference to the magnetic compass. Magnetic heading corrected for compass deviation is compass heading. Composite Structure: A type of aircraft structure made of plastic resins reinforced with strong, lightweight filaments. Compressor Section (Jet Engine): The rotor blade section of a turbine engine which acts as a compressor to pump air into the ʺburnerʺ, or ignition, section of the powerplants. Concourse (passenger): The passenger waiting area set apart from the main terminal where aircraft are parked for passenger loading and unloading. Conductive Hose‐ Type C: Fuel delivery hose which is manufactured utilizing conductive material to dissipate the static electrical charge created by fuel flowing through the hose. Conductivity: The ability to dissipate static electricity. ʺContactʺ: 1. Establish communication with (followed by the name of the facility and, if appropriate, the frequency to be used.) 2. A flight condition wherein the pilot ascertains the attitude of his aircraft and navigates by visual reference to the surface. Contaminants: Substances either foreign or native that may be present in fuel that detracts from its performance.
Contrail: A cloud‐like streamer frequently observed behind aircraft flying in clear, cold, humid air caused by the addition to the atmosphere of water vapor from engine exhaust gases. Controlled Airport: An airport with an operating tower. Controller: A person authorized to provide air traffic control services. Control Lock (external): see Rudder Lock Control Wheel: The pilotʹs mechanism or ʺsteering wheelʺ utilized to control aileron and elevator control movement. Convective Sigmet: A weather advisory concerning convective weather significant to the safety of all aircraft. Coordinated Universal Time: Time corrected for the seasonal variations in the earthʹs rotation about the sun. Coordinated Universal Time is the same as Greenwich Mean Time. Co‐Pilot: A licensed pilot serving in any piloting capacity other than pilot‐in‐command. ʺCorrectionʺ: An error has been made in the transmission and the correct version follows. Cowl Flaps: Movable flaps located at the exit of the cowling that houses an air‐cooled aircraft engine. Opening or closing the cowl flaps controls the amount of air flowing through the cowling, and this in turn controls the amount of heat removed from the engine cylinders. Cowling: The removable cover that encloses the aircraft engine. Customer Service Specialist: An employee of an FBO whose primary objective is to provide safe, professional, efficient and courteous service to their customers. Responsibilities include answering the telephone, handling air‐to‐ground radio communications, making hotel and rental car reservations, and handling requests for fuel, oil, oxygen, catering and other related ground services. Deadman Control: Hand held control used during single point pressure refueling operations to immediately stop the flow of fuel at any time. Defense Energy Support Center: U. S. Governmental agency responsible for the procurement of aviation fuels and services for government aircraft utilizing civilian airports. Defueling: Refers to the removal of fuel from an aircraft – regardless of the reason or quantity. Deicing: The removal of snow, ice and frost by a singular or combined process of mechanical, chemical or thermal means.
Deice Fluid: Specialized chemical fluid designed and utilized to remove and/or inhibit the formation of snow and ice from aircraft and control surfaces. There are a number of fluid types with varying viscosities and each is designed to meet the particular needs of the aircraft and the weather conditions. Some types may be mixed with water and heated prior to application while others may simply be applied in their original state. Deicing Boots (aircraft): Rubber devices found on the leading edges of wings and tail surfaces, as well as the inner portions of propellers. They are designed to inflate and break up ice which has formed over the ʺbootsʺ during flight. The boots have a number of small tubes which run lengthwise and are inflated from engine bleed air. Density: The amount of mass (weight) in a unit volume of a material. Department of Transportation: The United States regulatory government agency which oversees, promotes, coordinates, and develops research for the nations transportation industry that includes the Federal Highway, Railroad and Aviation Administrations. DESC: see Defense Energy Support Center Differential Pressure: The difference in pressure readings (PSI) taken on the inlet and outlet sides of a filter vessel. Also, referred to as Delta P or written as P. Direct Reading Differential Pressure Gauge: A pressure gauge that senses the pressure on the inlet and outlet sides of a filter vessel and automatically displays the difference in the two pressures. Direct User Access Terminal Systems: An automated pilot self‐ briefing and flight plan filing system. For pilots with access to a computer, modem, and touch tone telephone, the system provides direct access to a national weather data base and the ability to file flight plans without contact with a flight service station. Dispatch: see Aircraft Dispatch. Displaced Threshold: A threshold that is located at a point on the runway other than the designated beginning of the runway. Dissolved Water: Water that is in solution in the fuel. This water is not free water and cannot be removed by conventional means. Distance Measuring Equipment: Equipment (airborne and ground) used to measure, in nautical miles, the slant‐range distance of an aircraft from the DME navigational aid. DME: see Distance Measuring Equipment
Dome Covers: The top opening(s) on a refueler or transport truck that provide(s) access to the interior of the tank. Dome covers are intended to be used for visual inspection of the tank and verification of fuel type and product level. DOT: see Department of Transportation Down Burst: A strong down draft which induces an outburst of damaging winds on or near the ground. Damaging winds, either straight or curved, are highly divergent. The sizes of down bursts vary from one‐half mile or less to more than 10 miles. An intense down burst often causes widespread damage. Damaging winds, lasting five to 30 minutes, could reach speeds as high as 120 knots. Down Wash (helicopter): The air that is forced in an accelerated and downward motion as a result from the operation of the main rotor blades. Drag: The rearward acting force which resists the forward movement of the airplane through the air. Drag acts parallel to and in the same direction as the relative wind. Draw Bar Pull: The pulling strength or towing capacity of a tow vehicle (tug) rated in pounds. Drain Tubes: Clear plastic tubing that runs from the roll over rails down the front of a refueler tank, or the piping that extends down through the ladder at the rear of the tank. DUATS: see Direct User Access Terminal Systems. Dust Cap (Nozzle): A plastic or metal cap designed to cover over wing and single point nozzles in an effort to prevent an accumulation of dust, water and other contaminants from entering the nozzle area. EFAS: see En Route Flight Advisory Service Effluent: The stream of fluid at the outlet of a filter, filter separator, or any other piece of equipment. EI: see Energy Institute Elevator: A movable, horizontal control surface hinged to the rear of the tail section. Used for the pitch (up and down) control of the aircraft. ELT: see Emergency Locator Transmitter Emergency Locator Transmitter: A radio transmitter attached to the aircraft structure which operates from its own power source on 121.5 MHZ and 243.0 MHZ. It aids in locating downed aircraft by radiating a downward sweeping audio tone, two to four times a second. It is designed to function without human action after an accident.
Emergency Shut‐Off: a safety device to stop product (fuel) flow, via rapid valve closure or pump shut‐down. Empennage: The tail section of an airplane including all fixed and moveable surfaces. Empty Weight: The weight of the basic airplane, the structure, powerplant, fixed equipment, all fixed ballast and unusable fuel, undrainable oil, and hydraulic fluid. Energy Institute: The Energy Institute serves society with independence, professionalism and a wealth of expertise in energy matters, creating a home for energy professionals and a scientific and technical reservoir for industry. Engine Inlets (Intake): The forward portion of the engine cowling or nacelle which takes in air for engine combustion. Enroute Flight Advisory Service: This service, also known as flight watch, is designed to provide, upon pilot request, timely weather information pertaining to his type of flight, intended route of flight, and altitude. Entrained Water: Small droplets of free water in suspension that may make fuel appear hazy. Estimated Time En Route: The estimated flying time from departure point to destination (liftoff to touchdown.) Estimated Time of Arrival: The time the flight is estimated to arrive at the gate (scheduled operators) or the actual runway ʺonʺ times for nonscheduled operators. Estimated Time of Departure: The time the flight is estimated to depart at the gate (scheduled operators) or the actual runway ʺoffʺ times for nonscheduled operators. ETA: see Estimated Time of Arrival ETD: see Estimated Time of Departure ETE: see Estimated Time Enroute Exhaust Manifold: That part of the exhaust system closest to the engine. It collects gases from the engineʹs exhaust ports and passes them downstream to the muffler through a series of tubes. ʺExpediteʺ: Used by ATC when prompt compliance is required to avoid the development of an imminent situation. FAA: see Federal Aviation Administration. Fairing: Additions to any structure to reduce drag.
FAR: see Federal Aviation Regulation. FBO: see Fixed Base Operator Feathered Propeller: A propeller whose blades have been rotated so that the leading and trailing edges are nearly parallel with the aircraft flight path to stop or minimize drag and engine rotation. This term is used to indicate shutdown of a reciprocating or turboprop engine due to malfunction. Federal Aviation Administration: The Federal Aviation Administration is part of the Department of Transportation of the United States government. The responsibility of the FAA is to promote safety in the air. This is done by both regulation and education. Federal Aviation Regulation: Regulations established by the Federal Aviation Administration. These regulations are the rules which govern the operation of aircraft, airways, and airmen. Ferry Flight: A flight for the purpose of: 1. Returning an aircraft to base. 2. Delivering an aircraft from one location to another. 3. Moving an aircraft to and from a maintenance base. Filter: A device used to remove solid contaminants from fuel. Filter elements: A generic term given to various decontaminant media installed in various types of pressure vessels, i.e., coalescer elements, separator elements, clay bags, clay canisters, and micronic elements. Filter Membrane Test: see Millipore Test. Filter Separator: see Filter types. Filter types: 1. Micronic Filter: Essentially composed of a vessel containing a set of filtration elements, with the purpose of removing solid particles. Micronic filters are rated for the smallest sized particles that they are designed to remove, normally varying in the range of 2 to 75 microns, with a 5 micron rating normally used. These filters are generally constructed of pleated impregnated paper and/or a combination of paper and other media, such as glass fibers. The solid contaminants are primarily removed on the inlet surface of the filter media. Furthermore, a micronic filter would normally be located upstream of either a clay filter or filter separator to remove particulate contamination prior to its entrance into either of the other types of filtration, thus improving the filter ʺlifeʺ of both the clay filter and filter separators. 2. Clay Filter: A vessel designed to use clay, either in bulk or in replaceable cartridges, which by adsorption will pick up surface active agents (surfactants), color bodies, and very fine particles in the fuel, not otherwise removable, and ensure a MSEP or WSIM rating and clarity (cleanliness) necessary for servicing
modern aircraft. The removal by absorption of surfactants is dependent on an intimate contact of fuel and clay and on the residence time of fuel in the clay bed. Based on this factor, clay filters are normally designed for a maximum flow per cartridge of seven (7) gpm. The presence of free water in the fuel is the primary cause for a reduction in the life of clay. For this reason it is advisable that clay filters be located at points in the system where the presence of water is minimized. Further, clay filters should be located upstream of filter separators for two reasons: (1) to protect downstream filtration and water coalescing equipment from the deactivating effect of surfactants and other contaminants; and (2) to ensure the downs t ream filtration of clay granules that may have been picked up by the fuel in passing through the clay filter. 3. Filter Separator Filter: A vessel containing filter elements which will continuously remove dirt and water from aviation fuels to the extent necessary to minimize residual contamination. The fuel is passed through two stages of filtration, the first stage coalescers (upstream), being of very thick finely woven material (paper, fiber glass, etc.) which traps dirt down to the very finest particles sizes (usually nominally rated at 0.3 microns for into‐plane operations) and at the same time forces the smallest droplets of suspended mater to combine into large drops. These larger drops will more readily ʺfall outʺ of the fuel and are assisted to do so at the second stage separators (downstream), which is normally made up of a fine gauze Teflon‐coated metal screen. Based on the above design characteristics, filter separators are normally installed as the final filtration unit in the fuel handling system (in some cases monitor filters are used in place of filter separator filters). 4. Monitor Filter: A vessel containing filter elements which will continuously remove dirt and water from aviation fuels to the extent necessary to minimize residual contamination. The fuel is passed through one set of elements of very thick finely woven material(paper, fiber glass, etc.) which traps dirt down to the very finest particle sizes (usually nominally rated at 0.3 microns for into‐plane operations) and at the same time through an absorbent material which locks in any free water. Based on the above design characteristics, monitors are normally installed as the final filtration unit prior to fuel entering an aircraft. Fire Extinguisher: A device containing an extinguishing agent that can be expelled under pressure for the purpose of suppressing or extinguishing a fire. Extinguishers may be hand held (portable), mounted onto a cart with wheels (portable) or fixed in a specific location, i.e., hangar. Fire Point: The lowest temperature at which a vapor‐air mixture will continue to burn after it is ignited. This is generally only a few degrees above the flash point. Firewall: Fire resistant bulkhead between the engine and the rest of the aircraft.
First Officer: The pilot who is second in command. Also may be called co‐pilot. Fixed Base Operator: An individual or firm operating at an airport and providing general aircraft services such as maintenance, storage, ground and flight instruction, fuel, charter, aircraft service, aircraft sales and other ground services. Flame Front: The outermost edge of the chemical reaction of a fire. Flameout: Unintended loss of combustion in turbine engines resulting in the loss of engine power. Flammable: Refers to any liquid with a Flash Point below 140ºF (60ºC). Flammable range: The range between the least and the greatest amounts of flammable vapor in a given quantity of air which will explode or burn when ignited by a spark or flame. It is possible, such as in a completely closed container or tank of Avgas, to have a vapor‐air mixture which has too much vapor and is unable to support combustion. The combustible range for AVGAS is from approximately 2.5% to over 20% by weight. Flap: An auxiliary wing surface at the rear portion of the wing. Its purpose is to increase angle of attack or descent without increasing airspeed, by creating drag. Flash Point: The lowest temperature at which a liquid gives off sufficient vapors to form a flammable mixture in air. For Jet‐A this is approximately 100ºF (38ºC) and for AVGAS it is approximately ‐50ºF (‐46ºC). Flight Attendant: A member of the flight crew who’s primary responsibility is passenger safety. Flight Crew: Those members of the aircrew whose primary concern is the operation and navigation of the aircraft and its safety in flight. Flight Deck: The fuselage compartment of the aircraft which houses the flight crew and various aircraft controls and instruments to be used for operating the aircraft. Flight Engineer: A flight crew member on a large multiengine aircraft who performs non‐flying duties with reference to the aircraft powerplants, systems, fuel management and ground servicing. Flight Line: That portion of the ramp that is designated and utilized for the arrival and departure of aircraft. Flight Plan: Specified information relating to the intended flight of an aircraft that is filed by the flight crew orally or in writing with an FSS or an ATC facility.
Flight Recorder: A general term applied to any instrument or device that records information about the performance of an aircraft in flight or about conditions encountered in flight. Flight recorders may make records of airspeed, outside air temperature, vertical acceleration, engine rpm, manifold pressure, and other pertinent variables for a given flight. Flight Service Station: Air traffic service facilities within the National Airspace System that provide preflight pilot briefings and en route communication with IFR flights; assist lost IFR/VFR aircraft; assist aircraft having emergencies; relay ATC clearances, originate, classify, and disseminate Notices to Airmen (NOTAMʹs); broadcast aviation weather and NAS information; receive and close flight plans; monitor radio NAVAIDS; notify search and rescue units of missing VFR aircraft; and operate the national weather teletypewriter systems. In addition, at selected locations, FSSʹs take weather observations, issue airport advisories, administer airmen written examinations, and advise Customs and Immigration of transborder flights. Flight Standards District Office: An FAA field office serving a designated geographical area and staffed with Flight Standards personnel who have the responsibility for serving the aviation industry and the general public on all matters relating to the certification and operations of general aviation aircraft. Flight Watch: see En Route Flight Advisory Service Floating Suction: A floating intake device used in a tank for drawing product from the upper level of the fuel. FOD: see Foreign Object Damage Foreign Flag Air Carrier: An air carrier other than a U.S. flag air carrier in international air transportation. ʺForeign air carrierʺ is a more inclusive term than ʺforeign flag air carrierʺ including those non‐U.S. air carriers operating solely within their own domestic boundaries. In practice, the two terms are used interchangeably. Foreign Object Damage: Damage to a gas turbine engine caused by some object being sucked into the engine while it is running. Free Water: Water in the fuel other than dissolved water. Free water may appear in the form of droplets or haze suspended in the fuel (entrained water) and/or a water layer at the bottom of the container holding the fuel. Free water may also exist in the form of an emulsion that may be so finely dispersed as to be invisible to the naked eye. Freezing Point: The lowest fuel temperature at which the fuel is 100% liquid (there are no crystals). FSDO: see Flight Standards District Office
FSS: see Flight Service Station. Fuel additives (icing inhibitors): Prevent the formation of ice resulting from water coming out of solution at low temperatures and from water condensing in fuel tank. They have also been found to be an effective barrier to micro biological growth. Ethylene glycol monomethyl ether is specified for most military fuels and is permissible in commercial turbine fuels. Caution: Since excessive or improper injection of additive may lead to filter elements being disarmed, injection should take place downstream of filter separators prior to entering aircraft. Fuel Cabinet: An enclosed above ground unit which contains equipment enabling fuel to be dispensed into aircraft. Fuel Dumping: Airborne release of usable fuel. This does not include the dropping of fuel tanks. Fuel Farm: see Fuel Storage Facility (System) Fuel Remaining: A phrase used by either pilots or controllers when relating to the fuel remaining on board until actual fuel exhaustion. Fuel Siphoning: Unintentional release of fuel caused by overflow, puncture, loose cap, etc. Fuel Storage Facility (System): The storage tanks, associated facilities and equipment required for the storage and dispensing of aviation fuel at an airport. This equipment would include off‐load and refill hoses, deadman controls, pumps, piping, meters, filter vessels, bonding cables, etc. Fuel Tanks: Containers that are designed and constructed as either individual units or as an integral part of the aircraft structure; i.e., fuselage, wing. There are two basic types; 1. Bladder; specialized synthetic rubber and fabric material, which are collapsible and self‐sealing, and are located within the structure of the aircraft. 2. Integral; sealed areas of the aircraft structure (aluminum or composite) that do not utilize internal bladders. Fuel Venting: see Fuel Siphoning Fuselage: The body, or central structural component of an airplane. Fuselage Tank: A fuel tank located within the fuselage section of the aircraft. Galley: That part of the aircraft where food, beverages, dinnerware and utensils are stored, refrigerated, heated and prepared. General Aviation: That portion of civil aviation excluding those classified as air carrier, regional/commuter and military.
Glass Cockpit: A cockpit in which electronic visual displays are used instead of conventional instruments. Glide Slope: Provides vertical guidance for aircraft during approach and landing. ʺGo Aheadʺ: Proceed with your message. Not to be used for any other purpose. ʺGo Aroundʺ: Instructions for a pilot to abandon his approach to landing. Additional instructions may follow. GMT: see Greenwich Mean Time GPU: see Ground Power Unit Gravity: It is the pulling force that tends to draw all bodies to the center of the earth. Greenwich Mean Time: Mean solar time at the 0º meridian, the meridian that passes through the Royal Observatory in London England. Greenwich mean time (GMT) is also known as Zulu time and Universal Time. Gross Weight: Empty weight plus useful load is the gross weight of the airplane at takeoff. When an airplane is carrying the maximum load for which it is certificated, the takeoff weight is called the maximum allowable gross weight. Ground Power Unit: A piece of aircraft support equipment which can be connected to an aircraft on the ground to supply electrical power for system operation when the engine(s) or APU is/are not operating. Ground Speed: The speed of an aircraft relative to the surface of the earth. Ground Visibility: The prevailing horizontal visibility near the earthʹs surface. Grounding: A method of ensuring that the same electrical potential exists between the ground and a unit (i.e., refueler; transport truck; fixed facility; etc.) by connecting the unit via a conductive wire or cable to a grounding rod or other device. Hangar: A building used to store, secure and house aircraft in which maintenance services such as repair, engine overhaul and general maintenance may be performed. Hazardous Weather Information: Summary of significant meteorological information (sigmet/WS), convective significant meteorological information (convective sigmet/WST), urgent pilot weather report (urgent pirep/UUA), center weather advisories (CWA), Airmetʹs meteorological information (airmet / WA), and any other weather such as isolated thunderstorms that
are rapidly developing and increasing in intensity, or low ceilings and visibilities that are becoming widespread which is significant and are not included in a current hazardous weather advisory. Heat of Combustion: The net heat of combustion provides knowledge of the energy content of fuel available for conversion from heat into mechanical energy. Aircraft design and operation depend upon a certain predetermined minimum amount of heat energy. A reduction in available heat energy below this specified limit is accompanied by an increase in fuel consumption with corresponding loss of range. The net heat of combustion is conveniently computed from the aniline gravity product and total sulfur content. Helicopter: A heavier‐than‐air flying machine that is supported in the air by aerodynamic lift produced by an engine driven rotor. Helicopter Main Rotors: A rotating wing‐like airfoil that provides the main lift and propulsion system for a helicopter. Helicopter Mast: The power shaft extending upward, from the helicopter engine or transmission, which provides power to the main rotor. Helicopter Tail Rotor: A vertical spinning wing‐like airfoil mounted at the rear of the tail boom which controls the yaw axis (side‐to‐side movement) of a helicopter. Helipad: A small, designated area, usually with a prepared surface, on a heliport, airport, landing/takeoff area, apron/ramp, or movement area used for takeoff, landing, or parking of helicopters. High Performance Aircraft: An aircraft that has all the following is considered high performance: 1. More that 200 horsepower 2. Retractable landing gears 3. Flaps 4. Controllable pitch propeller Horizontal Stabilizer: The horizontal surface of an aircraft positioned either low or high on the empennage that controls the pitch (nose up or down) attitude of the aircraft. Hot Refueling: see Rapid Refueling Hot Start: An engine start, or attempted start, which results in the turbine temperature exceeding the specified limits. It is caused by an excessive fuel‐to‐air ratio. Hover Taxi: Used to describe a helicopter or VTOL aircraft movement conducted above the surface and in ground effect at airspeeds less than approximately 20 knots. (The actual height may vary.)
ʺHow do you Hear me?ʺ A question relating to the quality of the transmission, or to determine how well the transmission is being received. Hydrant Cart (hydrant dispenser): A mobile unit with the same characteristics as a hydrant service vehicle, however it requires a powered vehicle to move it. Hydrant Dispenser: see hydrant cart and hydrant service vehicle. Hydrant Service Vehicle (hydrant dispenser): A mobile unit containing meters, filtration equipment, hoses, etc. used to connect the hydrant system to the aircraft. Hypoxia: State of oxygen deficiency in the body sufficient to impair functions of the brain and other organs. ICAO: see International Civil Aviation Organization . IFR: see Instrument Flight Rules ILS: see Instrument Landing System IMC: see Instrument Meteorological Conditions. Inboard Fuel Tank (s): Inboard fuel tank(s) that may be located inboard of the engines or inboard of other fuel tanks. Influent: The stream of fluid at the inlet of a filter, filter separator, or any other like‐piece of equipment. This is the opposite of effluent. Inhibitor: A substance, the presence of which, in small amounts, in a petroleum product prevents or retards undesirable chemical changes from taking place in the product, or in the condition of the equipment in which the product is used. In general, the essential function of inhibitors is to prevent or retard oxidation or corrosion. Instructional Flying: Any use of an aircraft for the purpose of formal instruction with a flight instructor aboard. Instrument Approach: A series of predetermined maneuvers for the orderly transfer of an aircraft under instrument flight conditions from the beginning of the initial approach to a landing, or to a point from which a landing, may be made visually. Instrument Flight Rules: Rules governing the procedures for conducting instrument flight, a term used by pilots and controllers to indicate type of flight plan. Instrument Landing System: A precision instrument approach system which normally consist of the following electronic components and visual aids:
1. Localizer 2. Glide slope 3. Outer Marker 4. Middle Marker 5. Approach Lights Instrument Landing System Categories: 1. Category I (CAT I): An ILS approach procedure that provides for approach to a height above touchdown of not less than 200 feet, and with runway visual range of not less than 1,800 feet. 2. Category II (CAT II): An ILS approach procedure that provides for approach to a height above touchdown of not less than 100 feet and with runway visual range of not less than 1,200 feet. 3. Category IIIA (CAT IIIA): An ILS approach procedure that provides for approach without a decision height minimum and with runway visual range of not less than 700 feet. Instrument Meteorological Conditions: Meteorological conditions expressed in terms of visibility, distance from cloud, and ceiling less than the minimums specified for visual meteorological conditions. International Civil Aviation Organization: A specialized agency of the United Nations whose objective is to develop the principles and techniques of international air navigation and to foster planning and development of international civil air transport. Interlock: A system for ensuring that a fueling vehicle cannot be driven away from an aircraft unless the hoses are disconnected and properly stowed ‐ usually linked to the braking system of a refueler or hydrant service vehicle. Intersecting Runways: Two or more runways that cross or meet within their lengths. ʺI Say Againʺ: The message will be repeated. J Spout: A specially designed fuel nozzle for jet refuelers, used to reduce the possibility of aircraft misfueling. JATO: see Jet Assisted Takeoff Jet Assisted Takeoff: An auxiliary rocket or jet thrust system that supplements normal engine power during takeoff. Jet Blast: Jet engine exhaust (thrust stream turbulence.) Jet Engine: A gas turbine producing forward thrust by accelerating exhaust gases rearward : reaction propulsion. Jet Fuel (Jet Turbine Fuel) Types: 1. Jet‐A: A narrow cut kerosene; standard commercial jet fuel in the U.S.
2. Jet‐A1: A narrow cut kerosene, like Jet‐A, but has a lower freezing point. Used outside the U.S., and is the fuel of choice on long haul flights where the fuel temperature drops close to the freeze point. Usually includes a static dissipater. 3. Jet‐B: A wide cut kerosene, with ʺgasoline typeʺ components present. Used widely in Canada, with static dissipater and has a very low flash point. 4. JP‐4: A wide cut kerosene, like Jet‐B, but with ʺallʺ the additives: corrosion inhibitor, static dissipater, anti‐icing additive. Was issued in 1951 by the U.S. Military (phased out in 1995 and replaced by the higher flash point, safer JP‐8). 5. JP‐5: A narrow cut kerosene, like Jet‐A, but with a higher flash point (140F (60C) min.). This is the fuel used by the U.S. Navy aircraft. It has corrosion inhibitor and anti‐icing (di‐EGME) additives, but not the static dissipater. Was issued in 1952 by the U.S. Military for use on naval aircraft. JP‐5 products are manufactured to meet US Military MIL‐T‐5624 specification. 6. JP‐8: A narrow cut kerosene, like Jet‐A1, but with ʺallʺ the additives: corrosion inhibitor, static dissipater, anti‐icing additive. Was issued in 1979 by the U.S. Military for use by the air force (replacing JP‐4). JP‐8 products are manufactured to meet US Military MILT‐ 83133 specification. Jet Propulsion: A method of propulsion produced when a relatively small mass of air is given a large amount of acceleration. Jet Stream: A migrating stream of high‐speed winds present at high altitudes. Jet Turbine Fuel: A kerosene‐type jet turbine fuel with a boiling range of approximately 315º to 525ºF (175º to 273ºC), a flash point of 100ºF (38ºC) or above, and a freeze point of ‐53ºF (‐47ºC) for JET A‐1 and ‐40ºF (‐ 40ºC) for JET A. JET A is considered a Flammable Class II liquid. These products are manufactured to meet Specification ASTM D1655 or Defense Standard 91/91 and/or other local government specification. Jetway: A moveable passenger walkway or bridge that connects the airport terminal concourse to an aircraft. Knot (KT): A measure of speed used in aerial navigation. One Knot = 1.151 statute miles per hour. Landing Gear Lock Pins: Metal pins that lock the landing gear in the extended position to prevent accidental gear collapse during towing operations. Lateral Axis: Also known as the pitch axis of the aircraft. Drawn from wing tip to wing tip, an imaginary line drawn through the center of the aircraft. Lavatory: A common term for an aircraft restroom facility. There are two lavatory system types found in general aviation aircraft; (1) portable lift‐out and (2) permanently installed systems.
Leading Edge: The forward edge of an airfoil. Leading Edge Slats: see Slat Lift: The sum of all the aerodynamic forces acting on an aircraft at right angles to the flight path. When the aircraft is in steady level flight the lift is equal and opposite to the weight of the aircraft. Lighted Airport: An airport where runway and obstruction lighting is available. Light Gun: A hand held directional light signaling device which emits a brilliant narrow beam of white, green, or red light as selected by the tower controller. The color and type of light transmitted can be used to approve or disapprove anticipated pilot actions where radio communication is not available. The light gun is used for controlling traffic operating in the vicinity of the airport and on the airport movement area. Lightning (calculating the distance): To calculate the distance to lightning activity, count the number of seconds from the lightning flash to the sound of thunder. Every five seconds of elapsed time between the flash and the sound of thunder represents a distance of one mile. Formula: Time (seconds) divided by 5 = Distance (miles) Line Service Specialist: An employee of an FBO whose primary objective is to provide safe, efficient, professional and courteous service to their customers. They are responsible for providing a wide range of aircraft and customer support services including refueling, towing, oxygen servicing and other ground support services. Load Adjustment: Refers to the correction of a fuel load delivered to an aircraft as part of the original operation, i.e., before fueling equipment is disconnected. All load adjustments where product removal of the aircraft is involved must be treated as a defueling operation. Load Factor: The ratio of the total airload acting on the gross weight of the aircraft. Localizer: The component of an ILS which provides course guidance to the runway. Local Traffic: Aircraft operating in the traffic pattern or within sight of the tower, or aircraft known to be departing or arriving from flight in local practice areas, or aircraft executing practice instrument approaches at the airport. Locker (fuel) Tank: Fuel tanks located in the nacelle, aft of the engine. Longitudinal Axis: Also known as the roll axis of the aircraft.
Drawn from nose to tail, an imaginary line through the center of the aircraft. Low Approach: An approach over an airport or runway following an instrument approach or a VFR approach, including the go‐around maneuver where the pilot intentionally does not make contact with the runway. Mach Number: The ratio of true airspeed to the speed of sound. (738 mph at msl) Main Fuel Tank: The fuel tanks of the aircraft that are the primary source of fuel for the engine(s). Material Safety Data Sheet: Chemical and material manufacturerʹs data that includes information regarding hazards, including handling procedures, and disposal requirements. ʺMaydayʺ: The international radiotelephony distress signal. When repeated three times, it indicates imminent and grave danger and that immediate assistance is requested. Mean Sea Level: The datum used for measuring altitude. It is the average height of the surface of the sea. Microbial Growth: A living organism that requires water as a source of carbon (food) plus various trace minerals for their existence. Microbiological growths are better able to survive in kerosene, jet or heavy middle distillates, due to chemical composition of these fuels; however, gasoline and Avgas systems are not immune. Microburst: A small down burst with outbursts of damaging winds extending 2.5 miles or less. In spite of its small horizontal scale, an intense microburst could induce wind speeds as high as 150 knots. Micron (Micrometer): A unit of linear measurement. One micron is equal to 0.000039 inches (or 1/1000th of a millimeter) and approximately 35,400 microns equals 1 inch. For example, the average human hair is about 100 microns in diameter. Micronic Filter: see Filter Types. Middle Marker: A marker beacon that defines a point along the glide slope of an ILS normally located at or near the point of decision height (ILS Category I). Millipore Fuel Test (Filter Membrane Test): A standard test in which fuel is passed through a small filter membrane housed in a plastic holder. The cleanliness of the fuel can be determined by examining the membrane.
Mineral Oil: A non‐ashless dispersant oil with a mineral base. It is used primarily during the break‐in period of a new or rebuilt reciprocating aircraft engine. Minimum Fuel: Indicates that an aircraftʹs fuel supply has reached a state where, upon reaching the destination, it can accept little or no delay. This is not an emergency situation but merely indicates an emergency situation is possible should any undue delay occur. Minimums: Weather condition requirements established for a particular operation or type of operation. Misfueling: The accidental fueling of an aircraft or refueling vehicle tank with an improper grade, type, or contaminated product. ʺMonitorʺ: When used in communication transfer, listen on a specific frequency and standby for instructions. Under normal circumstances, do not establish communications. Movement Area: The runways, taxiways, and other areas of an airport/heliport that are utilized for taxiing/hover taxiing, air taxiing, takeoff, and landing of aircraft, exclusive of loading ramps and parking areas. At those airports/heliports with a tower, specific approval for entry onto the movement area must be obtained from ATC. MSDS: see Material Safety Data Sheet MSL: see Mean Sea Level Multi‐engine: An aircraft having more than one engine. Multi ‐ Viscosity Oil: An ʺall‐seasonʺ reciprocating engine oil that is designed to maintain optimum engine lubrication at a wide range of operating temperatures and conditions. ʺNʺ Number: see Tail Number Nacelle: An enclosed compartment in an aircraft in which an engine is mounted. NAS: see National Airspace System National Airspace System: The common network of U.S. airspace; air navigation facilities, equipment and services, airports or landing areas; aeronautics charts; information and services; rules, regulations, and procedures; technical information, manpower and material. Included are system components shared jointly with the military. National Fire Protection Association: (NFPA) NFPA 407: Standard for Aircraft Fuel Servicing. http://www.nfpa.org/index.asp.
National Transportation Safety Board: An independent Federal Agency whose function in civil aviation is to investigate aviation accidents; report publicly on their cause or probable cause; and to review on appeal the suspension, revocation, or denial of operating certificates, documents, or licenses issued by the FAA administrator. NDB: see Nondirectional Beacon ʺNegativeʺ: ʺNo,ʺ or ʺPermission not granted,ʺ or ʺThat is not correct.ʺ NFPA: see National Fire Protection Agency Nondirectional Beacon: An L/MF or UHF radio beacon transmitting nondirectional signals whereby the pilot of an aircraft equipped with direction finding equipment can determine their bearing to or from the radio beacon and ʺhomeʺ on or track to or from the station. Nose gear Collar: A collar that surrounds the nose landing gear designed to provide strength and to separate the lower portion (extension) of the gear from the top of the strut. Nose gear Torque Link Scissors: A scissor like mechanism that connect the top portion of the nose landing gear to the bottom. Provides steering support and control to the nose wheel. No Tail Rotor Type: Term used to describe a helicopter which does not require a tail rotor. NOTAM: see Notice to Airmen NOTAR: see No Tail Rotor Type. Notice to Airmen: A notice containing information (not known sufficiently in advance to publicize by other means) concerning the establishment, condition, or change in any component (facility, service, procedure of, or hazard in the National Airspace System) the timely knowledge of which is essential to personnel concerned with flight operations. NTSB: see National Transportation Safety Board. Octane (rating number): Grades of gasoline, including aviation grades that are given a rating that is a numerical measure of the anti‐knock properties of a specific grade of gasoline. Open Hose Discharge Capacity: The maximum discharge volume of a given hose if opened to the atmosphere. Outboard Fuel Tanks: Fuel tanks that are located outboard from the fuselage and/or engine. Outer Marker: A marker beacon at or near the glide slope intercept altitude of an ILS approach. It is normally located four
to seven miles from the runway threshold on the extended centerline of the runway. Over Wing Refueling: A method of gravity refueling which is accomplished by adding fuel to tanks individually through filler openings on the wings, or on the top or side of the fuselage (aircraft or helicopters). Parallel Runways: Two or more runways at the same airport whose center lines are parallel. In addition to runway number, parallel runways are designated as L (left) and R (right) or, if three parallel runways exist, L (left), C (center), and R (right). Particulate Matter: Solid contaminants (e.g., dirt, rust, scale, sand, etc.) sometimes found in fuel. PASS: The acronym for the procedure when operating a portable fire extinguisher; P = PULL (the safety pin). A =AIM (the nozzle). S = SQUEEZE (the trigger). S = SWEEP (the base of the flame). Personal / Pleasure Flying: Any use of an aircraft for personal purposes not associated with a business or profession, and not for hire. This includes maintenance of pilot proficiency. Phonetic Alphabet: A list of standard words used for each letter in the alphabet. The use of a standard phonetic alphabet assures that the letters are not misunderstood during radio transmission. Pilot Briefing: A service provided by the flight service station to assist pilots in flight planning. Briefing items may include weather information, NOTAMʹs military activities, flow control information, and other items as requested. Pilot Weather Report: A report of meteorological phenomena encountered by aircraft in flight. PIREP: see Pilot Weather Report Piston Engine: One of the common terms used for a reciprocating engine. Pitch: The nose, up and down, attitude of an aircraft controlled by the horizontal stabilizer or elevator. Pitot Tube: (pronounced pee‐toe) An open ended tube mounted either on the leading edge of the wing or nose of the aircraft that is aligned with the relative wind. The impact pressure on the open pitot tube affects the pressure in the pitot chamber. Any change of pressure on the pitot chamber is transmitted through a line connected to the airspeed indicator which utilizes impact pressure for its operation. Plexiglass: A trademark name for lightweight, transparent plastic. It is often used for aircraft windshields.
Position Lights: Aircraft lights that provide a means by which pilots can determine the general direction of movement of other aircraft during night or inclement weather operations. This lighting configuration consists of a red light on the left wingtip, a green light on the right wingtip, and a white light on the tail. Potable Water: Drinking water which is designated for human consumption and is drawn from outlets which meet the drinking water regulations. Powerplant: The complete installation of an aircraft engine, propeller, and all accessories needed for its proper functioning. Pre‐check: A device used to check the operation of the automatic high level shut‐off on aircraft and refuelers. Precipitation: Any or all forms of water particles (rain, sleet, hail, or snow) that fall from the atmosphere and reach the surface. Pressure Refueling: see Single Point Refueling. Pressure Regulator Liquid Control: A mechanism on a refueler that regulates or controls the amount of pressure for the fuel delivery hoses. Pressurized Fuel Tanks: A fuel tank pressurized with air to control fuel flow. Prop Wash (blast): The air which is pushed backwards from moving propeller(s). Propeller: A device for propelling an aircraft that has blades on an engine‐driven shaft and that, when rotated, produces by its action on the air a thrust approximately perpendicular to its plane of rotation. Propeller Arch: see Blade Radius PSI: Pounds per square inch. Pusher Propeller (prop): A propeller mounted on the aft side of the engine or wing that pushes the aircraft through the air. Quick Disconnect: A type of hose coupling that can be undone quickly and easily. Radial Engine: An older type of ʺreciprocatingʺ (piston) engine whereby the engine cylinders are positioned around a single crankshaft which is located at the center of these cylinders. A radial engine installed in an aircraft operates on aviation gasoline (AVGAS). Radio: 1. A device used for communication.
2. Used to refer to a FSS; i.e., ʺSeattle Radioʺ is used to call Seattle FSS. Radome: A strong, electrically transparent housing, used to enclose a radar antenna and protect it from the wind and weather. Ramp: see Apron Rapid Refueling: The refueling of a helicopter while an onboard engine is operating. Reaction Area: The area of a fire in which chemical vaporization and flame production occurs. ʺRead Backʺ: Repeat my message back to me. Relative Wind: The direction of airflow with respect to an airfoil or an object. Reciprocating Engine: An internal‐combustion engine in which a piston or pistons moving back and forth work upon a crankshaft or other devices to create rotational movement. It is referred to as a ʺreciprocatingʺ engine because many of the internal moving parts move forward and back, or reciprocate. A reciprocating engine installed in an aircraft operates on aviation gasoline (AVGAS). Refueler (Fueler): A mobile vehicle carrying aviation fuel in bulk for delivery to an aircraft, fitted with pumps, hoses, and filtration equipment. Registered Active General Aviation Aircraft: A civil aircraft registered with the FAA that has been flown one or more hours during the previous calendar year. Excludes aircraft owned and operated by commercial air carriers in scheduled, non‐ scheduled, or charter service or aircraft in excess of 12,500 pounds maximum gross takeoff weight that are owned and operated by a commercial operator certificated by the FAA to engage in intrastate common carriage. Relative Density: see Specific Gravity Relaxation Time: The period of time that fuel is allowed to flow in a system, so that the electrostatic charge (i.e., generated by fuel passing through a filter) in fuel can dissipate, or ʺrelaxʺ, to a safe level. Remain Over Night: Term indicating the aircraft and/or flight crew will terminate flight at last destination and will depart at a later date. Residual Heat: The heat remaining after the use or burning of an object. An example would be the heat remaining in aircraft brakes after landing and taxi.
Retrofit: To modify, improve or change an aircraft or itʹs components. Rime Ice: The formation of a white or milky and opaque granular deposit of ice formed by the rapid freezing of supercooled water droplets as they contact an aircraft or object. Roll: The movement of an aircraft around its longitudinal axis (nose‐to‐tail). Also referred to as an aerobatic aircraft maneuver. RON: see Remain Over Night Route: A defined path, consisting of one or more courses in a horizontal plane that aircraft traverse over the earth’s surface. RSA: see Runway Safety Area Rudder: The movable control surface mounted on the trailing edge of the vertical fin of an airplane. The rudder is moved by foot operated pedals in the cockpit, and movement of the rudder rotates the airplane about its vertical axis. Rudder Lock: An external device used to secure the tail rudder while the aircraft is parked. A rudder lock is designed to prevent damage to the tail rudder and rudder cables from the wind. Rudder Pedals: Foot pedals located in the cockpit used by the pilots to control the rudder (yaw) of the aircraft in flight and for taxiing and braking of aircraft when on the ground. Runway: A defined rectangular area on a land airport prepared for the landing and takeoff run of aircraft along its length. Runways are normally numbered in relation to their magnetic direction, rounded off to the nearest 10 degrees; e.g., ʺRunway 08ʺ (080 degrees), ʺRunway 36ʺ (360 degrees). Runway in Use/Active Runway/Duty Runway: Any runway or runways currently being used for takeoff or landing. When multiple runways are used, they are all considered active runways. Runway Safety Area: A defined surface surrounding the runway prepared, or suitable, for reducing the risk of damage to airplanes in the event of an undershoot, overshoot, or excursion from the runway. ʺSay Againʺ: Used to request a repeat of the last transmission. Usually specifies transmission or portion thereof not understood or received. Seal: Constitutes a non‐corrosive wire tie utilizing a lead disk (as a tamper proof device) bearing the impression of authorized party. Utilized as a security measure to control the unauthorized opening of a transport trucks unloading manifolds/valves. Second Officer: see Flight Engineer
See and Avoid: A visual procedure wherein pilots of aircraft flying in visual meteorological conditions (VMC), regardless of type of flight plan, are charged with the responsibility to observe the presence of other aircraft and to maneuver their aircraft as required to avoid the other aircraft. Separator Element: Allows passage of fuel, but repels free water droplets and is the second stage cartridge in a filter separator vessel. It is downstream of the coalescer cartridge. Settling Time: The time allowed for water or dirt entrained in the fuel to drop to the bottom of the storage tank. Short Takeoff and Landing Aircraft: An aircraft which, at some weight within its approved operating weight, is capable of operating from a STOL runway in compliance with the applicable STOL characteristics, airworthiness, operations, noise, and pollution standards. Shrouded Tail Rotor: The tail rotor of a helicopter that is enclosed by a shroud to improve safety and reduce noise. Sigmet: A weather advisory issued concerning weather significant to the safety of all aircraft. Sigmet advisories cover severe and extreme turbulence, severe icing, and widespread dust or sand storms that reduce visibility to less than 3 miles. Single Point Nozzle: A refueling nozzle that is connected directly to the aircraft and utilizes pressure to deliver jet fuel to the various tanks through a single connection. Single Point Refueling: A method of filling multiple fuel tanks in an aircraft from a single fueling point or multiple fueling points from the side of the fuselage or underside of the wings by means of pressure which provides higher fuel flow rates. Slat: A secondary control on an airplane that allows the airplane to fly at a high angle of attack without stalling. Solid Particles: Small solid or semi‐solid particles, sometimes referred to as silt or sediment, present in a fuel as a result of contamination by air‐blown dust, corrosion by products, fuel instability, or protective‐coating deterioration. Specific Gravity (Relative Density): The ratio of weight of any volume of fuel at 60ºF to the weight of an equal volume of water at 60ºF. Speed Brakes: Movable aerodynamic devices on aircraft that reduce airspeed during descent and landing. Stabilator: A single‐piece horizontal tail surface of an airplane. A stabilator serves the purposes of both the horizontal stabilizer and the elevators.
Stall: An aerodynamic condition in which the angle of attack, the angle at which the relative wind strikes the airfoil, becomes so steep the air can no longer flow smoothly over the airfoil. This disruption and breakdown of airflow causes a loss of lift. ʺStand Byʺ: Means the controller or pilot must pause for a few seconds, usually to attend to other duties of a higher priority. Also, means to wait, as in ʺstand by for clearance.ʺ The caller should reestablish contact if a delay is lengthy. ʺStand by is not an approval or denial.ʺ Static Electricity: An electric charge generated by fuel flowing through pipes, micro‐filters, etc. Very high voltages can be generated which may cause sparks. Static dissipater additives increase the fuel conductivity thus allowing charges to be dissipated quickly. Static Ports: Small external hole(s) located on the side of the aircraft fuselage, positioned at a 90 degree angle to the airflow, which measure atmospheric pressure and is subsequently used for both the altimeter and vertical speed indicator flight instruments. Static Wick: A small conductive graphite rod attached to the trailing edge of an aircraft surface designed to dissipate the static electrical charge which is built up on the aircraft as it moves through the air. STOL Aircraft: see Short Takeoff and Landing Aircraft Stop and Go: A procedure wherein an aircraft will land, make a complete stop on the runway, and then commence a takeoff from that point. Strut: The structure of an aircraft that provides additional strength to support the wing (wing strut). Also, found on the landing gear for strength (gear strut). Sump: A low point in a system for collection and removal of water and solid contaminants. Sump Fuel: The fuel removed from fixed facility tank and filter vessel sumps and mobile equipment sumps while performing routine quality control tests or maintenance on equipment. Sump (Thief) Pump: A small pump having a suction line which extends to the low point of a tank for the purpose of drawing off water which may have accumulated. Sump Sample: A drain sample obtained from the sump of a tank or filtration unit. Supplemental Air Carrier: An air carrier certificated in accordance with FAR Part 121, and providing nonscheduled or supplemental carriage of passengers or cargo, or both, in air
transportation. Also referred to as nonscheduled or charter air carriers. Surfactants: Surface Active Agents, are emulsifiers, detergents, foaming agents, etc., which will ʺdisarmʺ filter separators and render them ineffective. The presence of surfactants can be detected by visual inspection of drain samples. Observation of the interface between fuel and water will show a silvery, shiny film. Upon shaking such a sample in a clean glass bottle, particles of the film may stick to the glass in the fuel phase and may not settle out. Synthetic Based Oil: see Turbine Oil TAF: see Terminal Aerodrome Forecast Tail Boom: An extension of the empennage of an aircraft that supports the control section of the tail rudder. Tail Dragger: Aircraft having a tail wheel. Tail Height: The maximum tail height as stated in the aircraft manufacturerʹs specifications. Tail Number: The aircraft registration number typically located on the tail of the aircraft. Tail Stand: A support device placed under the tail of an aircraft to prevent the aircraft from tipping on its tail during loading, refueling or maintenance operations. Tail Wheel: A small, steerable wheel mounted at the aft end of the fuselage of an airplane equipped with a conventional landing gear. The tail wheel supports the aft end of the airplane when it is on the ground. Tank Hatches: see Dome Covers Taxi: The movement of an airplane under its own power on the surface of an airport. Also, it describes the surface movement of helicopter equipped with wheels. Taxiway: A paved strip that parallels the runways. Aircraft move along the taxiways from the terminal to the end of the runway so they will not interfere with aircraft using the runway for takeoff and landing. TCDS: see Type Certificate Data Sheet. Terminal Area: A general term used to describe airspace in which approach control service or airport traffic control service is provided. Terminal Aerodrome Forecast: A report established for the 5 statute mile radius around an airport utilizing the same descriptors and abbreviations as the METAR report.
Terminal Radar Service Areas: Areas where participating pilots can receive additional radar services. The purpose of the service is to provide separation between all IFR operations and participating VFR aircraft. Tetrahedron: A device normally located on uncontrolled airports and used as a landing direction indicator. The small end of a tetrahedron points in the direction of landing. At controlled airports, tower instructions supersede the indicator. ʺThat Is Correctʺ: The understanding you have is right. Threshold: The beginning of that portion of the runway usable for landing. Thrust: The thrust produced by a propeller or jet. Thrust Reverser: A component of a jet engine, usually mounted at the aft end, which is designed to partially reverse the thrust of the engine in order to slow the aircraft during the landing roll. Tie‐down: The securing of an aircraft to a ramp, using fixed restraint ropes or chains. Tip Tanks: Aircraft fuel tanks which are attached to the end, or tip, of each wing. ʺTop Offʺ: A common refueling term referring to the filling of an aircraft tank to its maximum level. Top Sample: A sample taken about 6 in. (15 cm.) below the surface of the fuel in a tank. Total Operations: All arrivals and departures performed by military, general aviation, commuter/air taxi, and air carrier aircraft. Touch and Go: An operation by an aircraft that lands and departs on a runway without stopping or exiting the runway. Tow Bar: A device used to connect an aircraft to a tow vehicle (tug) for the movement of aircraft. Tower: A terminal facility that uses air/ground communications, visual signaling, and other devices to provide ATC services to aircraft operating in the vicinity of an airport or on the movement area. Authorizes aircraft to land or take off at the airport controlled by the tower or to transit the Class D airspace area regardless of flight plan or weather conditions (IFR or VFR). A tower may also provide approach control services (radar or non‐radar). Traffic Pattern: The traffic flow is prescribed for aircraft landing at, taxiing on, or taking off from an airport. The components of a typical traffic pattern are; upwind leg, crosswind leg, downwind leg, base leg and final approach:
1. Upwind Leg ‐ A flight path parallel to the landing runway in the direction of landing. 2. Crosswind Leg ‐ A flight path at right angles to the landing runway off its upwind end. 3. Downwind Leg ‐ A flight path parallel to the landing runway in the direction opposite to landing. The downwind leg normally extends between the crosswind leg and the base leg. 4. Base Leg ‐ A flight path at right angles to the landing runway off its approach end. The base leg normally extends from the downwind leg to the intersection of the extended runway centerline. 5. Final Approach ‐ A flight path in the direction of landing along the extended runway centerline. The final approach normally extends from the base leg to the runway. Trailing Edge: The back edge of an airfoil, such as a wing, a helicopter rotor, or a propeller blade. It is the edge that passes through the air last. Transport Truck (Tank Truck): A vehicle used to transport product (i.e., fuel) from a terminal to another terminal or airport. Tricycle Landing Gear: A landing gear configuration that incorporates a total of three gears: two main and one nose gear. Trim Tab: A small control tab mounted on a primary control surface. The trim tab is adjustable in flight to change the aerodynamic load on the control surface. TRSA: see Terminal Radar Service Areas Turbine Fuel: see Jet Fuel Turbine Oil: A special chemical formulated synthetic based product which is designed to operate within the extreme temperatures of a turbine engine. Turbocharger: An exhaust‐gas‐driven air compressor used to increase the power of a reciprocating engine. Turbofan Engine: A jet engine with a large intake fan at the front. This design makes the engines more fuel efficient and quieter than the early pure jet engines. Turbojet Aircraft: An aircraft having a jet engine in which the energy of the jet operates a turbine which in turn operates the air compressor. Turboprop Aircraft: An aircraft having a jet engine in which the energy of the jet operates a turbine which drives the propeller. Turn Limit (nose gear): The maximum allowable side‐to‐side limit, measured in degrees, i.e.; 90 degrees, in which the nose gear may be turned without causing damage to the collars, strut, steering mechanism, etc.
Type Certificate Data Sheet: The official specifications of an aircraft, engine, or propeller issued by the Federal Aviation Administration. Ultralight Vehicle: An aeronautical vehicle operated for sport or recreational purposes that do not require FAA registration, an airworthiness certificate, nor pilot certification. They are primarily single‐occupant vehicles, although some two‐place vehicles in certain airspace requires authorization from ATC. Uncontrolled Airport: An airport without an operating control tower. Undercarriage: The landing gear of an aircraft. Underwing Refueling: see Single Point Refueling. Unicom: A nongovernment communication facility which may provide airport information at certain airports. Locations and frequencies of unicom are shown on aeronautical charts and publications. Unloading Control Seal: see Seal. Unloading Manifold: A system of piping and multiple openings installed onto a transport tanker truck designed for the unloading of product (fuel). U.S. Flag Carrier: Air carrier holding a certificate issued by the Department of Transportation, and approved by the President, authorizing the carrier to provide scheduled operations over a specified route between the United States (and/or its territories) and one or more foreign countries. Useable Fuel: The quantity of fuel that can be consumed by the engines prior to fuel exhaustion. The amount of useable fuel on an aircraft is typically less than the total fuel onboard because fuel pumps drain fuel from a level above low areas of the tank and sump drains. UTC: see Coordinated Universal Time. Ventral Fin: An external component found underneath the aft end of the aircraft which is used to improve stability during flight. Ventral Fuel Tank: A fuel tank located at the aft end of the aircraft and is usually designated as an auxiliary tank. ʺVerifyʺ: Request confirmation of information. Vertical Axis: A straight line running vertical through the aircraft around which the aircraft rotates. Vertical Stabilizer: The fixed vertical surface in the empennage of an airplane. The vertical stabilizer, or fin, helps produce directional stability in the airplane.
Vertical Takeoff and Landing Aircraft: Aircraft which are designed to take‐off and land vertically without the need for a lengthy runway area. VFR: see Visual Flight Rules. VFR Conditions: Weather conditions equal to or better than the minimum for flight under VFR. Viscosity: A fluids’ internal resistance to flow. Visibility: The ability, as determined by atmospheric conditions and expressed in units of distance, to see and identify unlighted objects by day and lighted objects by night. Visibility is reported as statute miles, hundreds of feet or meters. Visual Check: A field test to confirm the general acceptability of product. To be acceptable, fuel shall be of the correct color and be visually clear, bright, and free from particulate matter and undissolved water at normal ambient temperature. Visual Flight Rules: Rules that govern the procedures for conducting flight under visual conditions. Also used in the United States to indicate weather conditions that are equal to or greater than minimum VFR requirements. In addition, it is used by pilots and controllers to indicate type of flight plan. Visual Meteorological Conditions: Meteorological conditions expressed in terms of visibility, distance from clouds, and ceiling equal to or better than specified minima. VMC: see Visual Meteorological Conditions. Voltage: Sometimes also called electric or electrical tension and is the difference of electrical potential between two points of an electrical or electronic circuit, expressed in volts. VOR: A ground‐based electronic navigational aid transmitting very high frequency navigation signals, 360 degrees in azimuth, oriented from magnetic north. Used as a basis for navigation in the National Airspace System. VTOL Aircraft: see Vertical Takeoff and Landing Aircraft. Wake Turbulence: Phenomena resulting from the passage of an aircraft through the atmosphere. The term includes vortices, thrust stream turbulence, jet blast, jet wash, propeller wash, and rotor wash both on the ground and in the air. Water Detection System (Water Defense System): A device which senses a predetermined level of free water in filter separator sumps, and automatically stops the flow of fuel to prevent downstream contamination.
Water Finding Paste: A special chemical paste which will change color when it comes into contact with water. It is primarily used to determine the presence of water in fuel storage tanks. Water Methanol: An alcohol based additive which is injected into an engine to improve the engineʹs performance during takeoff. Water Slug: A large amount of free water in a fuel line. As with any water within aviation systems, immediate action must be taken to remove the water. Weather Advisory: In aviation weather forecast practice, an expression of hazardous weather conditions not predicated in the area forecast, as they affect the operation of air traffic and as prepared by the NWS. Wet Wing: A wing fuel tank that utilizes the structure of the wing to hold fuel versus the use of a separate rubberized bladder or aluminum tank installed within the wing. Wheel Pants: A common term for fixed landing gear coverings designed to reduce drag around the gear. Wheel Wells: The area or openings located in the underside of the aircraft that house the wheels when the gear is retracted. White Bucket Test: A common term referring to a test which verifies that fuel does not contain any visible water drops or particulates, and is free of haze or cloudiness. This is also referred to as a ʺclear and brightʺ test. ʺWilcoʺ: I have received your message, understand it, and will comply with it. Wind Direction: The true direction from which the wind is blowing. Wind milling: When an engine fails during flight the movement through the air tends to keep the propeller rotating. The same effect may occur when turboprop aircraft, whose propellers are not secured, are parked on the ramp.
Wind shear: A change in wind speed and/or wind direction in a short distance resulting in a tearing or shearing effect. It can exist in a horizontal or vertical direction and occasionally in both. Windsock: A cone shaped cloth sleeve, mounted aloft, at an airport to be used for estimating wind direction and velocity. The larger opening points into the direction of the wind. Wing: Term applied to an airfoil designed to generate lift. Types of wings are: 1. Delta wing 2. Elliptical wing 3. High taper wing 4. Moderate taper wing 5. Pointed wing 6. Rectangular wing 7. Swept wing Winglets: Small, nearly vertical aerodynamic surfaces mounted on the tips of the airplane wings. Winglets produce large forces even at low angles of attack, which combined with the perpendicular local flow, provide a forward thrust component. Wingspan: The distance from one wingtip of an aircraft to the opposite wingtip. Working Tank: The fuel storage tank being used to supply fuel to refuelers or the hydrant system. Yaw: A flight condition of an aircraft in which the aircraft rotates about its vertical axis. Yoke: The type of pilotʹs control column in which aileron and elevator control is achieved through the rotational movement of a control wheel. ʺZʺ Time: see Zulu time. Zulu Time: An expression for Greenwich mean time, or Coordinated Universal time.
