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360° 30° 60° 90° 120° 150° 180° 210° 330° Safety First The Airbus Safety Magazine # 01 January 2005 360° 30° 60° 90° 120° 150° 180° 210° 330°
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EditorialY. Malinge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
NewsC. Courtenay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Go-Arounds in Addis Ababa due to VOR Reception ProblemsJ. Daney . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
The Importance of the pre-Flight, Flight Control CheckA. Urdiroz . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
A320 In-flight thrust reverser deploymentT. Thoreau . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Airbus Flight Safety Manager HandbookC. Courtenay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Flight Operations Briefing NotesC. Lemozit & M. Tremaud . . . . . . . . . . . . . . . . . . . . 23
Airbus Flight Safety Contacts/Organisation . . . . . . . . . . . . . . . . . . . . . 26
Dear Customers and Aviation SafetyColleagues,
Flight Safety has permanently improvedfrom one aircraft generation to another andthis trend continues.There are several factors that have led tothese positive results, one of them beingthe flow of information between the keyactors of the aviation community. Eventhough it is extremely difficult to quantifythe benefit of information sharing, no onecan dispute the positive effect it has.
To further develop this information sharing,we re-launch our safety magazine. This isthe objective of this first issue of the AirbusSafety Magazine called “Safety First”(which replaces the previously named“Hangar Flying” magazine).It is intended to issue this on a regular basisas a hard copy and we also intend to sendit electronically.
This is not just a forum for Airbus to passinformation to you. We want your participation.Send us articles that you think are worthsharing. We will de-identify the informationif requested.
I hope you will find useful information inthis first issue but we rely on your feedbackto tell us what you think and what youwould like to see included.
Yours sincerely,
Yannick MALINGEVice President Flight Safety
Yannick MALINGE
Vice President Flight Safety
EDITORIAL# 01 January 2005
CONTENT
Safety First# 01 January 2005
Safety First is published by Airbus S.A.S1, rond point Maurice Bellonte31707 Blagnac Cedex / France
Editors:Yannick Malinge, Vice President Flight SafetyChristopher Courtenay, Director of Flight Safety
Concept Design by HCSM Production by CITYCompo
Copyright: EI
Photos copyright Airbus Photos by ExM: Hervé BerengerPhilippe MascletHervé Goussé
Printed in France
© Airbus S.A.S. 2005 – All rights reserved. Confidential and proprietary documents.
By taking delivery of this Brochure (hereafter “Brochure”), you accept on behalf of yourcompany to comply with the following guidelines:
No other intellectual property rights are granted by the delivery of this Brochure thanthe right to read it, for the sole purpose of information.
This Brochure and its content shall not be modified and its illustrations and photos shallnot be reproduced without prior written consent of Airbus.
This Brochure and the materials it contains shall not, in whole or in part, be sold, rented, or licensed to any third party subject to payment.
This Brochure contains sensitive information that is correct at the time of going to press. This information involves a number of factors that could change over time, effecting thetrue public representation. Airbus assumes no obligation to update any informationcontained in this document or with respect to the information described herein.
Airbus SAS shall assume no liability for any damage in connection with the use of thisBrochure and of the materials it contains, even if Airbus SAS has been advised of thelikelihood of such damages.
Airbus Flight SafetyManager's Handbook
By: Christopher CourtenayDirector of Flight Safety
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Safety FirstThe Airbus Safety Magazine
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SAFETY FIRSTThe Airbus Safety MagazineFor the enhancement of safe flight through increased knowledge and communications.
Safety First is published by the Flight Safety Departmentof Airbus. It is a source of specialist safety informationfor the restricted use of flight and ground crew memberswho fly and maintain Airbus aircraft. It is also distributedto other selected organisations.
Material for publication is obtained from multiplesources and includes selected information from theAirbus Flight Safety Confidential Reporting System,incident and accident investigation reports, systemtests and flight tests. Material is also obtained fromsources within the airline industry, studies and reportsfrom government agencies and other aviation sources.
All articles in Safety First are presented for informationonly and are not intended to replace ICAO guidelines, standards or recommended practices, operator-mandated requirements or technical orders.
The contents do not supersede any requirementsmandated by the State of Registry of the Operator’s aircraftor supersede or amend any Airbus type-specific AFM,AMM, FCOM, MEL documentation or any other approveddocumentation.
Articles may be reprinted without permission, exceptwhere copyright source is indicated, but with acknowl-edgement to Airbus. Where Airbus is not the author, thecontents of the article do not necessarily reflect theviews of Airbus, neither do they indicate Company policy.
Contributions, comment and feedback are welcome.For technical reasons the editors may be required tomake editorial changes to manuscripts, however everyeffort will be made to preserve the intended meaning ofthe original. Enquiries related to this publication shouldbe addressed to:
AirbusFlight Safety Department (EI)1, rond point Maurice Bellonte31707 Blagnac Cedex - FranceE.mail: [email protected]: +33 (0)5 61 93 44 29
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Are you on the distribution list?If you are reading this you obviously have a copyof the magazine either in paper format orelectronically. We need to make sure that ourdistribution list is up to date so please contact usto give us your details. Do not assume that youreceived it this once so you will get it next time!If you are an Airbus customer then contact us giving your name, title, company, address, phoneand e-mail information and we will ensure that youregularly receive a paper and/or electronic copy ofthe safety magazine.
The plan is to issue a magazine on a regularbasis but for those who have e-mail contactssome articles could be sent out in between thefull magazine issues.
Contact: Mrs Nuria [email protected]: +33 (0) 561934429
Let us know what you think and do youhave inputs?
As already said this magazine is a tool to helpshare information. Therefore we rely on yourinputs. If you have ideas or desires for what is inthe magazine please tell us. If you haveinformation that we can share between us thenplease contact us. We are ready to discussdirectly with you.
Contact: Chris [email protected]: +33 (0) 562110284Mobile: +33 (0) 671631903
Flight SafetyConferenceAirbus’ annual flight safety conference was held inToulouse from 11th to 14th October 2004, bringingthe aircraft manufacturer and its customers togetherin a confidential forum that allows them to shareexperiences learned through in-service events.
Now in its eleventh year, the conference was alsoan opportunity for Airbus to raise awareness ofgeneral issues relating to the safe operation of itsaircraft. This year’s conference is the largest todate with 135 representatives from 83 airlines.Alain Garcia, executive vice-president, Airbusengineering, opened the three-day safetyconference for operators of all aircraft types.
As in previous years, a spirit of trust and opennessprevailed throughout the conference, despite thesensitive nature of some of the topics beingdiscussed. The open exchange of information byboth airlines and Airbus has proved to be asignificant contributor to safety enhancement.
Safety representatives from airlines who will beoperating the A380 when it enters service in 2006also received a special briefing related to the aircraft.
The questionnaires returned from the participantswere very positive with 100% of the returnsbelieving the conference objectives were achieved.There were comments on some points and theseare being reviewed for next year’s conference. One of the main concerns was the conferencefacilities. This point has been taken and as a resultthe date and venue for the next conference areconfirmed:
LISBON, Portugal 17th to 20th October 2005
There will be more news on the conference in thenext issue of the magazine.
NEWS
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The following article was provided by theinvolved Airbus operator and has beenreproduced with their agreement but has beende-identified. At the end of the article there isinformation on the Airbus policy concerning theuse of GPS position for Terrain Awareness andWarning System (TAWS). This policy was issuedin an OIT/FOT (ref: SE 999.0015/04/VHR dated05 February 2004).
The same crew and aircraft had been scheduledto operate the flight from **** to Addis AbabaBole Airport (HAAB) with a single en-route stopat****.
The first sector was operated without incidentand, after disembarking passengers and refuelling,continued to HAAB. On arrival overhead the AddisAbaba VOR/DME (ADS 112.90 MHz), the flightwas cleared to carry out a standard VOR/DMEapproach to runway 25L at Bole. Touchdownelevation at Bole was 7593’ amsl and the MDAfor the procedure 8020’ amsl. There were nocivilian radar facilities.
The VOR/DME indications had appeared normalup to the start of the procedure, but during theoutbound leg, ADS 092° radial, an unexpectedlarge correction left was required to acquire theradial. After flying the ADS DME 13nm arc, a leftturn was made to intercept the 249° inboundQDM and descent from 11200’ amsl commencedin accordance with the procedure. The VOR radial
started fluctuating during the descent andeventually the indications disappeared. With noadequate visual reference, a standard missedapproach was flown from a minimum altitude of8922’ amsl and the aircraft entered the hold overthe ADS. Once in the hold and after confirmingwith Bole ATC that the VOR/DME was serviceablethe crew carried out a navigation accuracy checkthat appeared normal and elected to carry out afurther approach. Once again, the VOR indicationfluctuated during the inbound leg and anothermissed approach was flown from a minimumaltitude of 8866’ amsl after which the aircraftdiverted to Djibouti. A brief EGPWS “Terrain Ahead”warning occurred as the go-around was initiated.
After refuelling at Djibouti, the commander elected to use his discretion to extend the flyingduty period and return to HAAB. On arrival atBole, a daylight visual approach was flown torunway 25L and a successful landing made. Itwas noted during this approach that the VORbearing information was in error up to 30° andthat any attempt to fly the procedural inboundQDM would have displaced the aircraft to theNorth of the required track.
The commander filed an Air Safety Report (ASR)as required by the company in the event of anygo-around. Normal company procedures alsorequired an inspection of flight data from theQuick Access Recorder (QAR) as part of the follow up to any ASR and the company FlightSafety Manager carried this out.
Go-Arounds atAddis Ababa due VORReception Problems
By: Jean DaneyDirector of Flight SafetyAs reported by an Airbus Operator and reproduced with their permission
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of the VOR transmitter had revealed a 2°error inthe radiation pattern and that an alternativetransmitter was in service. Calibration of thealternative transmitter appeared to have been bypilot report from GPS equipped inbound aircraftand it was stated that the pattern was correct.
At a subsequent meeting with the Flight SafetyOfficer of Ethiopian Airways it was stated thatthere had been concerns from Ethiopian Airwayspilots that the inbound leg of the 25L VOR/DMEprocedure was “taking aircraft too far north ofthe ideal track”. It was not clear whether theseconcerns had been relayed to the EthiopianCAA, although it was stated that EthiopianAirlines was putting pressure on the CAA tooinstall an ILS for this runway prior to the rainyseason that starts around July/August.
The following day, the company Flight SafetyManager was subsequently contacted by BoleATC and advised that the ADS VOR had beentaken out of service following a fault caused by theheavy rain that had occurred during that evening.The company flight for that day had alreadydeparted and was diverted to Khartoum. A furthercall from Bole ATC confirmed that the VOR wasback in service and fully serviceable. The divertedflight arrived at HAAB with no reported problems.
Addis Ababa BoleInternational Airport(HAAB)Bole Airport is located on the south western outskirts of the city of Addis Ababa, Ethiopia.The airport reference co-ordinates shown on theEAG Aerad chart are: N08 58.7 E038 47.9
Addis Ababa is situated on the Ethiopian plateauat an elevation of 7600’ amsl and is surroundedby areas of high ground rising to approximately11000’ amsl.
The airport has been undergoing significantdevelopment in recent years and has recentlyseen the construction of a new terminal buildingand the new 07R/25L runway. The new runwaylays parallel to and approximately 400m south ofthe original 07L/25R. The ADS VOR was movedto its current location south of the two runwaysduring the development.
In current operations 07R/25L is used as themain runway with the old runway designated astaxiway “Foxtrot”. However, 07L/25R is still usedas an active runway by local traffic.
The only instrument approach procedures currently available to the operator at the timewere the VOR/DME procedures for 25L and25R. Landings on runway 07R are achieved bycarrying out the 25L VOR/DME procedure andbreaking left for a visual circling approach to 07R.The Ethiopian CAA has promulgated a GPS/RNAVprocedure for runway 07R and will shortlypromulgate one for 25L. The involved operatordoes not currently hold an approval for GPS/RNAVapproaches. Full ILS procedures for both 25Land 25R are now promulgated.
In addition to the ADS VOR, there were two MFlocator beacons, ‘AB’ 333 KHz and ‘BL’ 352KHz, situated on the original ILS approach pathto 25R. There were no ILS procedurespromulgated for the airport at the time, althoughthe original 25R ILS localiser was believed to bestill radiating on 110.3 MHz. New aids have nowbeen installed as stated above.
The analysis revealed that at some point on bothapproaches the aircraft had passed over a ridgeof high ground not normally encountered on the25L approach. At the point at which the secondgo-around had been initiated the aircraft hadpassed over the ridge with a clearance of 55’ asshown by the radio altimeter recording. At notime were the crew aware of this close proximityto the ground.
A full company investigation into the circumstancesof the incident continued independently of theofficial investigations initiated by the state authoritiesconcerned and with the assistance of the AirbusFlight Safety Department. Following the outcomeof the company investigation, the company hasput in place measures to minimise the risk ofsimilar incidents which include:
• HAAB to be treated as a Category ‘C’ airport,
• Operations to HAAB to be conducted by GPSequipped aircraft only,
• Approach to be discontinued if VOR indicationsdiffer from GPS derived FMGS indications bymore than 5°,
• The MDA for the 25L VOR/DME procedureraised to 9380’ amsl (1790’ aal) in associationwith a minimum visibility of 5KM,
• Approach to be discontinued if no visual contactwith the runway approach lights at ADS DME5nm (FAF). (ie MAP is ADS 5DME)
Note: The last two restrictions have since beenrelaxed as confidence in the “ADS VORDME wasregained. The airport authorities have alsoinstalled an ILS on this runway and a newDVORDME facility in the area since this incidenttook place.
The incident aircraft has also been fitted with aGPS engine in the EGPWS computer as an interimmeasure, with a full GPS MMR upgrade scheduledfor early 2005.
NavigationalConsiderationsAll Airbus A320 aircraft are fitted with triple InertialReference Systems (IRS). The navigation functionis performed by the dual Flight Management &Guidance Computers using the outputs from theIRS and refining the combined IRS position withradio navigation aid or GPS satellite information.The involved aircraft is not fitted with GPS satellitenavigation equipment and the position refinementis taken from ground radio navigation aids only,typically DME/DME, VOR/DME or VOR/VORcrosscuts depending on local availability.
In the area of Addis Ababa the only suitable radionavigation aid was the “ADS” VOR/DME locatedbetween the two runways at Bole Airport atposition N08 58.7 E038 47.9. It follows, therefore,that any error in the transmitted data from thisVOR would result in a corresponding error in thecomputed FMGC position. Such errors couldresult from faulty operation of the VOR/DMEfacility, radio frequency interference with thetransmitted data or anomalous radiation causedby local terrain (sometimes referred to as “scalloping”).
The possibility of faulty airborne equipment hadto be considered but this is unlikely as similaranomalous VOR indication behaviour wasobserved during a subsequent approach byanother A320 fitted with a GPS. This latteroccurrence was witnessed by the Flight SafetyManager.
The incident was discussed with the Director ofthe Air Operations and Navigational AidsDepartment (DONAD) and the Head of SafetyInvestigations of the Ethiopian CAA. The formerstated that he was not aware of any otherreports of problems with the ADS VOR but thatan investigation would be carried out in responseto this particular report. On the following day averbal report was received that an examination
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Terrain ProfilesThe following approach and terrain profiles werederived using the data from the QAR. The pressurealtitudes recorded have been corrected for aQNH of 1027 HPa for Figure 1 and 1029 HPa forFigures 2 & 3.
Figure 2 shows the profiles for the first approachat HAAB. Notable points are the non-slopingnature of the terrain between 15nm and 6nm andthe high point at just over 5nm. There is also amarked valley at 9nm and a lesser one at 6.5nm.
Figure 3 shows the profiles for the secondapproach at HAAB. Here, the notable points areagain the flat terrain between 15nm and 7.5nmand the high point at just over 5nm. The river valleyis still apparent at 9nm, but has split into two.The terrain clearance at the point of go-around is55’.
Aircraft PositionThe only position information available from theQAR was the recorded FMGC latitude and longitude. Since the FMGC position was IRSposition corrected by radio position and the onlyradio position was based on the suspectVOR/DME facility, no reliance can be placed onthe accuracy of the recorded position information.
One point of interest was the behaviour of therecorded FMGC position immediately after eachgo-around. The standard missed approach procedure for the 25L VOR/DME approachstates “Left (max 185kt) as soon as practicableonto ADS 193R to 13500 5910 then right to ADSand hold or as directed”. (EAG Aerad Chart N1dated 20 FEB 03). On both go-arounds therecorded heading information suggests that the aircraft followed this procedure. The FMGCposition data, however, indicates a right turn immediately after each go-around followed laterby an abrupt left turn onto a southerly track.The crew report stated that during eachapproach the VOR indications were lost just priorto the go-around, but came back as the go-around proceeded. During the approachmade by the GPS fitted aircraft the followingbehaviour was observed:
TerrainConsiderationsThe airport is situated on a relatively flat plain at7600’ amsl. The level of the plain rises graduallyto the east attaining an elevation of approximately8500’amsl 15nm from the airport. There aresignificant high peaks around the airport asfollows:
• 10535’ amsl 010°T / 8nmBearings and distances are approximate
• 9646’amsl 025°T / 11nmfrom VOR/DME position
• 10167’ amsl 120°T / 11.5nm
• 9200’ amsl 230°T / 9nm
There is a significant ridge running approximately135°T from the first of the above peaks and running out into the plain at about 6nm from theVOR. This ridge is the one referred to in later sections of this report. A further ridge runsapproximately 215°T from the same peaktowards the eastern outskirts of the city. Thisruns out into the plain approximately 3.5nmnorth of the airport.
Terrain information is provided for the crew bythe following:
• EAG Aerad charts N1/N2these show “safety contours” and Sector SafeAltitudes for the four prime sectors within 25nmof the aerodrome reference point. At Addis, theSSA for all sectors is shown as 13500’. Nodetailed terrain information is shown.
• EAG Aerad Terrain ChartA large scale chart showing the main features ina large area around Addis. No fine detail ofterrain around the airport is shown.
• Military ONC ChartA 1:1000000 scale chart of the region
The involved aircraft is fitted with a HoneywellEnhanced Ground Proximity Warning System(EGPWS) with software to standard 428. TheEGPWS computer has been removed from theaircraft and an attempt made to download eventdata from it. This was initially unsuccessful dueto a fault condition at the time of removal. Theunit was returned to the OEM who achieved adownload in his workshop. During the subjectapproaches and go-arounds the crew heard onlyone EGPWS alert, a “Too Low Terrain” call justafter initiation of the second go-around believedto have been triggered by the Terrain ClearanceFloor mode. The QAR recorded a short durationMode 4 ”Too Low Terrain” warning at about thesame time.
This photograph shows the NW to SE ridge running down towardsthe approach path. It was taken from near the village ofLeghedadi 10nm NW of the airport looking WSW from a range ofapproximately 5nm.
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This picture shows the same ridge from a range of about 8nmfrom the NW of Leghedadi.
Figure 1 shows the profiles for the approach carried out on the return from Djibouti which wascarried out visually. The terrain profile is typicalfor a correct approach path with the characteristicgentle slope of the plain from west to east. Othercharacteristic features are the river valley at 6.5Dand the double depression on the final approachto the threshold.
The distance scale on this figure can be directlyrelated to DME distance from the “ADS”. InFigures 2 & 3, the 13nm marker can be taken as13D from the “ADS”, but other distances do notrelate to DME as the aircraft was not flyingtowards the DME facility. The distances havebeen corrected to take account of the varyinggroundspeed during each approach.
Figure 1
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1 IntroductionAs far as aeronautics systems are concerned,the pre-flight flight controls (F/CTL) check hasexisted since before the first powered flight. Itaims at ensuring that flight controls respond to the pilot inputs, i.e. with no jamming, ormovement limitation, or stiffness, or delayed orinadequate response. It is thus a key factor in thesafe operation of the aircraft.The pre-flight F/CTL check has been made on aflight basis by pilots since they flew an airplanefor the very first time.Being so familiar with it, one may fall in the trapof routine and neglect the importance of it. Onemay also believe that the aircraft’s self-monitoringcapabilities are sufficient to provide the adequateinformation, but they are not. Improper maintenanceor components failure are to be considered also.Here we review the scope of the pre-flight F/CTLcheck, and demonstrate based on in-serviceexamples, how topical it still is.
2 Scope of theF/CTL check
An efficient F/CTL check ensures that thesystems respond adequately:
1- In direction – for instance elevator movesdown when the control column or thesidestick is pushed;
2- In amount of travel, up to full deflection;3- In return to neutral;4- In feeling.
The importance of thepre-flight, flight controlscheck
By: Albert UrdirozFlight Safety Manager
• During the outbound leg of the procedure, theVOR bearing information correlated with theGPS derived FMGC data on the NavigationDisplay (ND).
• As the aircraft turned left to intercept the249°M track inbound to the VOR, the beambar initially moved in as expected to near centre.
• As the wings were levelled on a heading thatshould have followed the correct track, thebeam bar moved back out to the right and settled at about half to two thirds full scaledeflection.
• The crew flew by visual reference to the runwayusing the GPS derived navigation data to follow the correct inbound track and the VORindication remained steady at the deflectionstated above.
• At about 3.5D, the beam bar quickly movedback to the central position.
The two approaches flown during the incidentflight were both conducted in IMC with only oneglimpse of ground lights during the firstapproach.
Figure 4 on shows the track for the secondapproach.
On any Airbus aircraft, the F/CTL check involvesthe elevators, ailerons, spoilers and ruddercontrol systems. Not only the componentsactivated with the control wheel, control columnand pedals, but the whole system. Let us refer tofigure 1 and take the rudder axis of an A310 asan example in order to illustrate this comment.
Consider now each of the 4 items we have mentioned and review which systems are involved.
1- In direction;2- In amount of travel;3- In return to neutral;4- In feeling.
The majority of the components represented infigure 1 are involved:- Obviously rudder pedals, mechanical linkage
and servocontrols;- Any inopportune rudder trim that would shift
the rudder from neutral would be detected withcriteria 3;
- Artificial Feel Mechanism with criteria 4;- Detection of any offset from Yaw Damper
system with criteria 3;- Rudder Travel Limiting Systems with criteria 2.
We may come to similar conclusions on otheraxis, and/or other aircraft types. Note on fly-by-wiresystems, it would be electrical wiring instead ofmechanical linkage.
The F/CTL check is thus not limited to therelationship in between the servocontrols, observedwith the surface position indicators, and thecontrols at cockpit. The whole system is checked.
Figure 4
Green line = FMGC Position Plot from QARRed Line = Derived Still Air Plot Using Heading
and Ground Speed from QARBlue Pecked Line = 25L VOR/DME Procedure Outbound Track 094°TMagenta Pecked Line= 25L VOR/DME Procedure Inbound Track 251°T
Initially, as the procedure is commenced, theFMGC track and still track appear to be followingthe procedural 094°T track. The FMGC trackthen starts to deviate to the south and the aircraft is turned left to correct taking the still airtrack to the north of the required track. This correction brings the FMGC position slowly backto the required track, but the still air track is moving well north.
Airbus PolicyThis Airbus policy is concerning the use of GPSposition for TAWS operations. Note that theTAWS is also known as EGPWS (EnhancedGround Proximity Warning System) or T2CAS(Traffic and Terrain Collision Avoidance System).
The TAWS computer has an internally loadedterrain database and uses position informationfrom the FMS. The FMS uses ADIRU positionand radio position update. It can also use a GPSposition source when available. The use of the GPS with multimode receivers(MMR) provides improved navigation andsurveillance functions. Therefore Airbus stronglyrecommends the use of a GPS source in theglobal architecture of the TAWS system.
Airbus offers an upgrade package that includesinstallation of 2 multimode receivers (MMR) and2 GPS antennas.However some aircraft configurations may needupgrade of other aircraft equipment to make fullbenefit of the MMR system. The Airbus upgradeservices will define everything needed during theRFC/RFO process.
For more information see OIT/FOT ref SE999.0015/04/VHR, dated 05 Feb 2004
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Take-off was performed with the shift firstcompensated by inputs on the pedals and thenby the autopilot yaw actuator once autopilot wasengaged. But the rudder moved sharply to therudder trim position once the autopilotdeclutched and the aircraft experienced anunexpected and sudden bank.
Such an event is covered with criteria 3, rudderat neutral with controls (what includes ruddertrim) at neutral. There was no warning triggeredto the crew, but it could have been detected bycarefully performing the existing StandardOperating Procedures (SOP) F/CTL Check.
3.2 Response in opposite direction
We will here discuss an in-flight turn back due toInverted Roll Command experienced with an A320.
The F/CTL check was performed with noanomalies noticed by the crew. At take-off, theCaptain applied a lateral sidestick input to theright, but the aircraft banked to the left. The F/Otook over, and successfully landed the aircraft.
Upon troubleshooting, a maintenance error wasfound. A wiring inversion had been madebetween the transducer unit of Captain rollsidestick and ELAC 1, on both the COMMAND &MONITOR channel. With this double inversion,ELAC 1 was receiving consistent signals, andthus could not detect the anomaly and could nottrigger a warning to the crew (Figure 3).
3 Take-off afterF/CTL check failed
We will here go through some examples gatheredfrom in-service experience, when crew did notstrictly adhere to the golden rules of F/CTLcheck.
3.1 Surfaces not at neutral with controlsnot at neutral
Let’s come back on an event that was evoked inissue 7 dated October 2001 of Hangar flying undertitle “A310/A300-600 – Rudder trim incorrectindication – ATA 27”, and also commented inOIT/FOT Ref. AI/SE 999.0030/00/CL dated 14February 2000. At the end of the F/CTL check, rudder trimindicator (RTI) was showing some rudder triminput. However rudder and rudder pedals wereat neutral. Pedals and rudder trim are linked.
Rudder trim actuator (RTA) had to be at neutralalso. Indication was erroneous.
Rudder trim indication was manually broughtback to neutral with no further check. This shiftedthe rudder, the rudder trim actuator and the pedalsout of neutral.
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Figure 3: Cross connection of sidestick roll signals to F/CTLcomputer
The functional check required after performingAMM tasks had partially been performed on theF/O side only, and thus the anomaly was nodetected by mechanics. Crew missed the lastopportunity to detect it by not carefully performingthe existing SOP F/CTL Check.
This event was presented during the 8th flightsafety conference held in October 2001 (Item 15entitled “A320 crossed roll controls”). It was alsocovered with an OIT/FOT entitled “ATA 27 – In-flight turn back due to inverted aileron deflectionafter take-off”, Ref. AI/SE 999.0069/01/CL REV01 dated 15 June 2001.
3.3 Lack of response
Another example is an in-flight turn back due toreduced ability to turn left experienced just aftertaking off with an A320. Almost full left sidestickinputs were required in order to laterally controlthe aircraft. At 1500ft, ECAM warning “F/CTLSPLR FAULT” came up with all right hand rollspoilers shown inoperative.
During a previous maintenance task, R/H spoilers 2to 5 were left in the maintenance position. After lift-off, they deployed to the zero hinge momentpositions and would not respond to inputs.
Preventive instructions have been added inAMM, and monitoring has been improved to triggeran ECAM warning in such condition. But it couldalso have been detected by carefully performingthe existing SOP F/CTL Check (Figure 4).
Figure 4: Lack of response from RH spoilers to sidestick inputs
Figure 1 : A330 moder system schematic
Figure 2 : incorrect rudder trim indication
RTA, pedals and rudder at neutral
RTA0 deg
RTIR 10.0 deg
RTAL 10 deg
RTI00.0 deg
RTA, pedals and rudder shifted
At end of flight controls check
At take-off
COM
MON
MON
CPT F/OELAC 1
ELAC 2COM
No deflection of RH roll spoilers
4 Efficiency of theF/CTL check
Some events, including recent ones, havehighlighted the importance of the F/CTL check.Indeed anomalies were detected which required correction before flight, when aircraft systemsdid not trigger any failure warning to the crew.Here after are some of them.
4.1 Lack of response
A few events of this kind have been experiencedwith aircraft of the A340 family. The crew detectedduring the pre-flight F/CTL check that one elevatorwas stuck down (Figure 5). The loss of theelevator control was not indicated to the crew byany warning.
These events resulted from failure of the servo-control in damping mode failed. Investigatingthese events has allowed definition ofmodifications to both the servocontrols and theF/CTL computers in order to prevent similarevents. Appropriate ECAM warnings aretriggered for crew annunciation. For theseevents, detection was ensured by carefullyperforming the existing SOP F/CTL Check only. Additional information about these event isavailable with- OIT/ FOT Ref. SE 999.0149/03 dated
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17 December 2003 entitled “ATA 27– elevatordropped down – Cracked mode selector valvetransducer at servocontol in damping position”;
- OIT Ref. SE 999.0066/04/BB Rev. 01 dated 11June 2004 and FOT Ref. STL 999.0061/04dated 10 June 04 entitled “ATA 27 – Right elevatorstuck down in full pitch down position causedby double failure.
4.2 Limited deflection
One last example is an event of undue ruddertravel limitation on ground.
The Rudder Travel Limitation Unit (RTLU) hadfailed closed in the high-speed configuration.The ECAM warning “F/CTL TRAVEL LIM FAULT”dedicated to the monitoring of the RTLU positionwas not displayed.
Indeed, at that time, FCSC which is the computerthat controls the RTLU and PTLU did not monitortheir behaviour during phases when they are notelectrically supplied and thus not supposed tomove. However the RTL system failed and RTLUclosed during such a phase of no monitoring onground. Monitoring has since been reviewed.
The failure was thus detected only by performingthe existing SOP F/CTL Check, and the rightdecision to return to the gate could be taken.
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Figure 7: Extract of A330 SOP – FCOM 3.03.10 Rev. 19
5 Completion of theF/CTL check
All of the above-mentioned events haveconfirmed that the crew properly performingFlight Control Checks remains the last safety net.However, training feedback and line observationshave revealed that the F/CTL checks were notalways performed properly because:
- Checks were routinely performed;- The PF moved the sidestick too quickly and
the PNF had insufficient time to efficientlyperform the checks;
- The PNF may be out of the monitoring loop.
SOP F/CTL checks have been reviewed with areinforcement of the role of the PNF who now
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Figure 5NORMAL CONFIGURATION
Low speed position High-speed position
EVENT CONFIGURATION
Figure 6: Full rudder deflection not archieved
calls out the results of his/her visual check ofeach of the PF’s sidestick/rudder pedal stopsinputs. This allows the PNF to still closelymonitors the correct sense, full deflection andreturn to neutral of all surfaces as previouslyrecommended, and in addition:
- Avoids the PNF from being influenced by thePF callouts
- Ensures that the PNF efficiently checks allsurface motions
- Obliges the PF to pause the sidestick/rudderpedals at each stop
- Allows the PF to detect a failure, if callout isnot in line with the PF’s input.
The in-flight thrust reverser deployment is one ofthe most feared situation by all pilots. It hasalways been under the extensive scrutiny of boththe engines and airframe manufacturers as wellas by the Airworthiness Authorities. This particularattention was even reinforced after the tragicaccident which occurred on Lauda Air B767flight NG004 in May 1991. This has lead to theimplementation of additional modifications to further decrease the probability of occurrence ofsuch event.
Despite all protective measures in place, theevent described hereafter occurred in March2004 on an A320 aircraft equipped with IAEV2500-A1 engines.
Sequence of events:- While the aircraft was on a transit check for a
scheduled flight, airline’s maintenance found anhydraulic leak from the engine N° 1 inboardlower thrust reverser actuator.
- Airline’s maintenance deactivated the reverserfor an aircraft dispatch under M.E.L.
- In climb phase, approximately 15 nm from thedeparting airport, engine N° 1 reverser gotdeployed.
- As per check-list, engine N° 1 was shutdownby the crew
- Crew then made a safe precautionary landingback to departing airport.
Findings:- Upon landing, the engine N° 1 reverser was
found almost fully deployed.
A320 In-flight thrustreverser deployment
By: Thierry ThoreauDirector of Flight Safety
6 ConclusionIn comparison with conventional aircraft, "Fly bywire" architecture provides an additional flightcontrols systems monitoring in order to ensureflight controls availability and safe aircraft operation.
Airbus' priority is to continuously meet theseobjectives, if possible, via monitoring enhancements.However, EFCS monitoring features cannotpossibly detect all failure cases.
A comprehensive flight controls integrity checkrelies on the crew's accurate completion of pre-flight control checks.
The new SOP procedure increases the efficiencyof the F/CTL checks, in association with theF/CTL monitoring systems: The PF and PNF aredefinitively in the monitoring loop.
The key message Airbus would like to convey is:
TAKE YOUR TIME PROPER F/CTL CHECKS = SAFER FLIGHT
Note: The F/CTL checks have been discussedduring the 11th Flight Safety Conference held inToulouse in September 2004. CD's of this conference may be requested to the Nuria Soler,[email protected].
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- The thrust reverser sleeve locking pins (2) werenot found, while the lock-out assembly wasintact.
- After opening the fan cowls, both locking actuators were found lock wired in the unlockposition. The HCU was properly deactivated.
Figure 1
17
19
Operational aspectanalysis:Prior to engine start, the ECAM warning “ ENGXREVERSE UNLOCKED” was annunciated.
Flight data analysis:GMT:14.16.30 A/C takes off TLA are set toTOGA position - EPR reach 1.4 A/THR engages
GMT: 14.17.30 A/P 1 is engaged Altitude is1,700 ft AGL, TLA are set to CLB
GMT: 14.18.30 SLAT/FLAP conf clean isselected
GMT: 14.20.22 ENG 1 thrust suddenly dropsdown
ALT is about 6500 ft AGL – CAS = 250ktsThe a/c was in a left commanded turn. The rollangle was decreasing from around 10° with arate of 2°/sec.EPR actual, EPR command and EPR targetdecrease from 1.24 to 1.0 in 10 seconds (auto-idle logic activated due to a reverse deploymentbeyond 10%)A/THR disengagesConcurrently, VRTG decreases to 0.99g. Rollrate which was about 2°/sec (aircraft was in leftturn) reduces to 0.4°/sec ; LATG increases to0.05g. Rudder moves from 0 to -3DA (rightinput)
GMT: 14.20.32 ENG 1 TLA increasesWhen Engine 1 reaches Idle, crew moves TLA1up to 31DA, ENG1 intends to follow TLA1 position(short thrust increase) but continues to decreasedown to Idle (auto-idle logic)
GMT: 14.20.45 ENG 1 TLA decreasesCrew elects to retard TLA1 to Idle and increasesTLA2 to 35DA (MCT)
GMT: 14.21.25 Aircraft levels off Altitude is8000ft ; CAS increases to 262kts (maximumreached during this flight)
GMT: 14.21.59 ENG1 shut down Main ENG1parameters start to toggle, NCD parameters
GMT: 14.22.27 Auto thrust is reactivated
GMT: 14.42.25 Crew performs a manual single engine landing
Maintenance actionsanalysis:- The HCU deactivation was done properly
following the AMM procedure:• “A. Deactivation of the Thrust Reverser HCU”procedure.
- The following AMM procedure steps were notperformed , because it was not possible to doso while the thrust reverser actuators were lockwired in the unlocked position:•“B. Manually move the translating sleeves tothe fully retracted position”•“C. Lock the Left and the Right Translatingsleeves”
- Finally the last AMM procedure step was notdone.• “D. Put the locking actuators in the lockedposition”
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Actuator unlocked
Due to the combination of having:
- The HCU deactivated (leading to no hydraulicpower to the actuators)
- And the actuators not locked- And the lock-out bolts not properly installed on
the translating sleeves,
Lock pins missing
Figure 2
Figure 3
Figure 4
According to information received, maintenancepersonnel cancelled the “ENGX REVERSEUNLOCKED” message through the “EMER/CAN”button.Upon engine start, the “ENGX REVERSEUNLOCKED” warning was then displayed undercancelled cautions, while the ECAM showed“REV” Amber in EPR gauge and “STS” indication.
the translating sleeves were not locked andwere free to move under aerodynamic loads.
Per FCOM Standard Operating Procedure“cockpit preparation”, the ECAM controlpanel STS page must be checked to ensurethat INOP SYS display is compatible withMEL. In this case for ENGX REVERSEUNLOCKED, the MEL says “NO DISPATCH”.
However, the aircraft was dispatched with thethrust reverser unlocked and free to move underaerodynamic forces.
Less than 4 minutes after take-off, the engineN°1 auto-idle was activated. It activates oncethere is more than 10% opening of the reverser,and brings down the TRA to idle based on theinitial TRA position. This reverser opening detectionalso triggered the Auto thrust disconnection. TheAuto re-stow which is also normally triggeredwas not effective since there was no hydraulicpower due to the proper de-activation of theHCU.
As described in the Flight data analysis, therewas very little changes on aircraft flightcharacteristics. Based on the flight parametersevolution it is assumed that the thrust reverserdeployed slowly due to the aerodynamic forces(there was no hydraulic power due to HCU de-activation).
The aircraft maintained control with no upsetthroughout the event.
The engine was shut-down, then the Auto thrustwas re-engage, and an IFTB was made followedby an uneventful single engine landing.
21
Maintenance recommendations:It is absolutely necessary to strictly follow allsteps of the relevant AMM Thrust reverser de-activation procedure.
Furthermore, only the required tooling must beused (appropriate locking pins,…)
Finally, “ENG X REVERSE UNLOCKED” warningshould not be displayed following reverser deactivation.
2020
Figure 5: Normal Flight Condition
HCU Unlocked
Figure 6: Deactivated Flight Condition
HCU Locked
Operational recommendations:The “ENGX REVERSE UNLOCKED” and the“REV” Amber messages should not be presenton ECAM following a proper thrust reverserdeactivation. They are both NO DISPATCHwarnings.
In addition, the “EMER/CANC” button shouldonly be utilized to kill a permanent spuriouswarning.
Figure 7: Normal Flight Condition & Deactivated FlightCondition
Actuator locked
Figure 9: Normal Flight Condition
LockingPin Placeholder
Locking PinStowage
Figure 8: Maintenance Condition Only
Actuatorunlocked
Figure 10: Deactivated Flight Condition
Locking PinInstalled
Flight SafetyEnhancement – In Need of a Global ApproachAviation safety, measured in terms of number ofhull losses per departure, has reached a maturebut stable level.
Any further enhancement of this achievementrequires a systemic approach where the aircraft,the operations and the operating environmentare considered globally.
Introducing the FlightOperations BriefingNotes ConceptThe Flight Operations Briefing Notes have beendesigned to allow an eye-opening and self-correcting accident-prevention strategy.
The initial set of Approach-and-Landing FlightOperations Briefing Notes has been developedby Airbus in the frame of the Approach-and-Landing Accidents Reduction (ALAR) Task Forceled by the Flight Safety Foundation (FSF).
The wide acceptance of the Approach-and-Landing Briefing Notes by the pilots’ community
and the positive feedback received from customers have prompted Airbus to initiate thedevelopment of new sets of Briefing Notes, inorder to cover the entire flight profile and addressthe main threats and hazards to flight operationssafety.
Accident-preventionStrategyTo support this strategy, each Flight OperationsBriefing Note:
• Presents the subject and its associated hazardto flight operations safety, using backgroundinformation and statistical data;
• Emphasizes the applicable standards and bestpractices (e.g., standard operating procedures[SOPs], supplementary techniques, operationalrecommendations and training guidelines);
• Lists and discusses the operational and humanfactors that may cause flight crews to deviatefrom applicable standards;This section constitutes an eye-opener toassist the reader in assessing his/her ownexposure;
• Provides or suggests company accident-prevention-strategies and/or personal lines-of-defense;
This section will assist the reader in identifyingcompany or personal prevention strategiesand/or corrective actions;
Flight operationsbriefing notesA Tool For Flight Operations Safety Enhancement
By: Christophe LEMOZITManager Flight Operations Safety Enhancement, Customer Servicesand: Michel TREMAUDSenior Director Safety and Security, Customer Services
On many occasions, the Flight Safety Dept inAirbus were receiving request from newlyestablished and charter airlines for assistance insetting up a Flight Safety function.
At that time, Airbus being a manufacturer ratherthan an operator, felt we did not have thecompetence to offer this experience. However,there were many airlines around the world thatalready had in place a well run Flight Safetyfunction. So it was logical to request the well-established airlines to assist other airlines.
So the project was launched by Airbus to createa kind of guide book (a What to Do and How toDo) that would enable a newly appointed FlightSafety Manager to set up his function. We werequite fortunate at this time to recruit Mr DennisJohnson who had just retired from Virgin Atlanticas their Flight Safety Manager. Dennis was theprinciple author of what later became the AirbusFlight Safety Manager's Handbook. During thedrafting of this handbook, there were severalround-the-table reviews of the contents with several airlines who were kind enough to activelyparticipate; namely, Aer Lingus, AirtoursInternational, Gulf Air, Royal Jordanian, Transaertogether with many others (Airtours International,China Airlines, Costa Rica DGAC, Eyptair, TAMand TransAsia) sending in their comments.
The handbook was finally published in March1999 and up until today we still receive many
requests for copies. This handbook was laterused by GAIN as a basis to create an expandedversion. The book was so successful it was afinalist in the Flight International Safety awards.The award judges considered the Airbus approach“as just what the industry needs providing a firstclass template for any new flight safety operation". One major airline's senior air safetyinvestigator described it as "unique in its scopewhere all aspects of a flight safety managementprogramme are addressed, from corporate commitment through accident/incident investigations, to listings of available safetyresources".
If airlines wish to receive copies of this handbook, simply contact Airbus Flight Safety.Contact: Mrs Nuria [email protected].
Airbus Flight SafetyManager's Handbook
By: Christopher CourtenayDirector of Flight Safety
2322
• Takeoff and departure operations(e.g.: Understanding takeoff speeds, Revisitingthe stop or go decision, …),
• En-route climb and cruise management(e.g.: Managing buffet margin, overspeedprevention / recovery, …),
• Descent management(e.g.: Being prepared for go-around, …),
• Approach techniques(e.g.: Flying stabilized approaches, …),
• Landing techniques(e.g.: Preventing tail strike at landing, …),
• Ground handling(e.g.: Refueling with passenger on board, …),
• Cabin operations(e.g.: Managing smoke issues in cabin, emergency evacuation, …).
The Flight Operations Briefing Notes are progressively released on the Safety Libraryroom of the Airbus Safety First website:http://www.airbus.com/about/safetylibrary.aspThey should be also disseminated to customersonce a year on CD-ROM and paper format.
ConclusionFlight safety enhancement has been and will continue to be the result of technologicaldevelopments.
However, 85 % of accidents today are operationalevents that involve human performance at everystage of the safety chain.
By developing the concept of Flight OperationsBriefing Notes and by facilitating their widedissemination to all actors of the aviationcommunity, Airbus acknowledges that safetyawareness information is a key element in furtherenhancing flight safety.
CONTACTDETAILS
AIRBUS
Michel TREMAUDSenior Director Safety and SecurityCustomer ServicesTel: +33 (0)5 61 93 30 04Fax: +33 (0)5 61 93 29 [email protected]
Christophe LEMOZITManager Flight Operations SafetyEnhancementCustomer Services, Flight OperationsSupport & Line AssistanceTel.: +33 (0)5 62 11 82 90Fax: +33 (0)5 61 93 29 [email protected]
Line pilots should review and compare therecommendations, guidelines and awarenessinformation with their current practices andenhance their techniques and awareness level,as required.
Other actors in the global aviation system, suchas:• Air traffic control services;• Navigation state agencies;• Operational authorities;• Service providers; and,• Flight academies / flying colleges;
…should use the provision of the Flight OperationsBriefing Notes to evaluate their possiblecontribution to the enhancement of ground andflight safety.
What’s coming up?The release of the Briefing Notes will span overthe years 2004-2006 and will cover the followingdomains:
• Standard operating procedures(e.g.: Conducting effective briefings, …),
• Human Performance(e.g.: Enhancing situational awareness, errormanagement, …),
• Operating environment(e.g.: Bird strike threat awareness, …),
• Adverse weather operations(e.g.: Wind shear awareness, …),
• Runway and surface operations(e.g.: Preventing runway incursions, …),
• Supplementary techniques(e.g.: Preventing altitude deviations, …),
• Establishes a summary of operational keypoints and training key points;
• Refers to associated or related FlightOperations Briefing Notes; and,
• References related ICAO, U.S. FAR andEuropean JAR regulatory documents.
How to Use andImplement the FlightOperations BriefingNotes?The Briefing Notes should be used by airlines toenhance the awareness of various operationaland human factors, threats and hazards amongflight crews and cabin crews.
Management pilots should review, customize (asrequired) and implement the recommendations,guidelines and awareness information, in thefollowing domains:
• Operational documentation:
- Standard operating procedures; and,- Procedures and techniques / supplementary
techniques.
• Training:
- Simulator Training, to develop new scenariosfor line oriented flight training (LOFT) or special purpose operational training (SPOT);and/or,
- Crew resource management (CRM) training,to develop new topical subjects to supportCRM discussions.
• Safety-awareness Information:
- Flight crew bulletins;- Airline’s safety magazine articles;- Classroom lectures; and/or,- Stand-alone reading.
2424 25
27
Yannick MALINGEVice President Flight SafetyPhone + 33 (0)5 61 93 43 60Fax + 33(0)5 61 93 44 29E.Mail - [email protected] +33(0)6 73 19 53 50
The Airbus Flight Safety Team
26
Jean DANEYDirector of Flight SafetyHead of In-Service Safety & Incident InvestigationPhone + 33 (0)5 61 93 35 17Fax + 33(0)5 61 93 44 29E.Mail - [email protected] +33(0)6 08 67 02 48
Andre MAUMUSDirector of Flight SafetyHead of Safety Strategy DevelopmtPhone + 33 (0)5 61 93 71 57Fax + 33(0)5 61 93 98 21E.Mail - [email protected] +33(0)6 09 37 79 69
Geoff CORLETTFlight Safety ManagerPhone + 33 (0)5 61 93 40 76Fax + 33(0)5 61 93 44 29E.Mail - [email protected] +33(0)6 71 92 53 02
Albert URDIROZFlight Safety ManagerPhone + 33 (0)5 62 11 01 20Fax + 33(0)5 61 93 44 29E.Mail - [email protected] +33(0)6 21 50 14 65
Armand JACOBTest PilotOperational Advisor to the VicePresident Flight SafetyPhone + 33 (0)5 61 93 47 92Fax + 33(0)5 61 93 29 34E.Mail - [email protected] +33(0)6 22 10 36 09
Thierry THOREAUDirector of Flight SafetyHead of International CooperationPhone + 33 (0)5 61 93 49 54Fax + 33(0)5 61 93 44 29E.Mail - [email protected] +33(0)6 88 06 47 91
Christopher COURTENAYDirector of Flight SafetyHead of Safety InformationDisseminationPhone + 33 (0)5 62 11 02 84Fax + 33(0)5 61 93 44 29E.Mail - [email protected] +33(0)6 71 63 19 03
Panxika CHARALAMBIDESFlight Safety ManagerPhone + 33 (0)5 62 11 80 99Fax + 33(0)5 61 93 44 29E.Mail - [email protected] +33(0)6 03 03 42 85
Nuria SOLERFlight Safety Dept SecretaryPhone + 33 (0)5 61 93 45 19Fax + 33(0)5 61 93 44 29E.Mail - [email protected]
Michel PALOMEQUEFlight Safety AdvisorTo Single Aisle Chief EngineerPhone + 33 (0)5 62 11 02 85Fax + 33(0)5 61 93 44 29E.Mail - [email protected] +33(0)6 23 08 06 38
Jérôme PAULHETFlight Safety AdvisorTo Long Range Chief EngineerPhone + 33 (0)5 62 11 01 91Fax + 33(0)5 61 93 27 60E.Mail - [email protected] +33(0)6 23 08 06 26
Eric MICHONNEAUFlight Safety AdvisorTo Wide Body Chief EngineerPhone + 33 (0)5 62 11 80 40 / 09 79Fax + 33(0)5 61 93 48 28E.Mail - [email protected] +33(0)6 09 37 58 25
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