Airbus technical magazine March 2018
#61 FAST Flight Airworthiness Support Technology Already have the FAST app? Now get the latest news for customers via Newsfeed by Airbus.
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byAirbus byAirbus
FAST and Newsfeed by Airbus apps are downloadable to your preferred device Airbus technical magazine Already have the FAST app? #61 Now get the latest news for customers via Newsfeed by Airbus. FAST Flight Airworthiness Support Technology
Publisher: Alizée GENILLOUD Chief Editor: Deborah BUCKLER Design: PONT BLEU Engine Bleed Air System 04 Cover image: Sylvain RAMADIER Increasing reliability Printer: Amadio with preventive maintenance
Authorisation for reprinting FAST magazine articles A350 XWB composite 10 should be requested by email: [email protected] bonded repair New technology for new aircraft FAST magazine is available on internet www.aircraft.airbus.com/ support-services/publications/ Technical data 18 and on tablets or smartphones for maintenance ISSN 1293-5476 Taking efficiency to new dimensions
26 © AIRBUS 2018 All rights reserved. Proprietary document A350 XWB vertical
By taking delivery of this Magazine (hereafter ‘Magazine’), you accept on behalf stabiliser continuous joint of your company to comply with the following. No other property rights are granted Precision technology by the delivery of this Magazine than the right to read it, for the sole purpose of information. This Magazine, its content, illustrations and photos shall not be modified for attachment fittings nor reproduced without prior written consent of Airbus. This Magazine and the materials it contains shall not, in whole or in part, be sold, rented, or licensed to any third party subject to payment or not. This Magazine may contain market-sensitive or other information that is correct at the time of going to press. This information involves a number of factors which could change over time, affecting the true public Supporting ageing fleets 32 representation. Airbus assumes no obligation to update any information contained in this document or with respect to the information described herein. The statements Scheduling the unscheduled made herein do not constitute an offer or form part of any contract. They are based on Airbus information and are expressed in good faith but no warranty or representation is given as to their accuracy. When additional information is required, Airbus can be FAST contacted to provide further details. Airbus shall assume no liability for any damage in connection with the use of this Magazine and the materials it contains, FAST from the past 38 even if Airbus has been advised of the likelihood of such damages. This licence byAirbus byAirbus is governed by French law and exclusive jurisdiction is given to the courts and tribunals of Toulouse (France) without prejudice to the right of Airbus to bring proceedings for infringement of copyright or any other intellectual property right in any other court of competent jurisdiction. Airbus, its logo, A300, A310, A318, A319, A320, A321, A330, Around the clock, 39 FAST and Newsfeed by Airbus apps A340, A350, A380 and A400M are registered trademarks. around the world Photo copyright Airbus are downloadable to your preferred device Photo credits: Airbus Photographic Library, Airbus Corporate Heritage, Field representatives Master Films, Hervé Gousset, Philippe Masclet, Pascal Pigeyre, Jean-Baptiste Accariez 03 FAST#61 04 FAST#61 Increasing reliabilitywithpreventivemaintenance Air System Engine Bleed [email protected] AIRBUS Air andInertingSystemEngineer Benjamin CALVET Article by pressurisation andair intakede-icing. is thendistributedfor essentialfunctionssuchascabin This sub-systemdrawshotairfromtheengines, which the lastfiveyears. Operational Interruptions(OI)andcosts, as provenover Bleed AirSystem,operatorscansignificantly reduceboth By carryingoutpreventivemaintenanceon theEngine
Protection S stem at highpressure(44PSI)andhas3mainfunctions: This sub-systemprovidesconsumers*withhightemperatureair(200°C) System Bleed Air of theEngine An overview Fuel Tan Inertin S stem control Pressure regulation Pressure control Temperature Win Ice (ATA 30) Con itione Ser ice (ATA 47) Air S stem (ATA 21) Engine Bleed Air System1 (Pratt &Whitney, General Electric)
To startervalve systems Aircraft To startervalve Engine bleed push button (Rolls Royce) switch
(ATA 80) Starter (ATA 21) Pac Fan position regulating Monitoring Valve computer Pressure pressure valve Bleed check Over- valve valve IP Intermediate Pressure (IP) • • • which include: engine portsinordertoensuresufficientpressurisedairisprovided toconsumers* installed directlywithintheaircraftengine.Itallowsairtobebledfromseveral The EngineBleedAirSystemisasub-systemofthethat Auxiliary (including crossstarting) Cabin pressurisation Wing anti-icesystem Engine starting HP bleedvalve Power (ATA 49) pressurisation Unit Fan air valve Pressure Water tan High (ATA 38) (HP) exchanger overboard Precooler ThS ThC Sense line2 Sense line3 Sense line1 Sense line4 = = ThC
Solenoid Thermostat Temperature ControlThermostat Aircraft systems Temperature
ThS H raulics tan Pr Pt pressurisation Pressure Ground (ATA 38) Carts High • • • waste andwaterstoragetanks (ATA21) Pressurisation ofhydraulictank,aswell Cabin airgenerationandcoolingsystems Fuel TankInertingSystem(FTIS) (ATA 80) * Afunctionwhich‘consumes’bleedair. electro-pneumatic systems. programmes arefittedwith Systems whereasmorerecent full pneumaticEngineBleedAir and theA330ceoarefittedwith families suchastheA320ceo programme. Earliergeneration evolved witheachAirbusaircraft Engine BleedAirSystemshave Starter X A330neo X X A320neo X A350 A380 A340-500/600 A340 basic A330ceo A320ceo programme aircraft Airbus (ATA 21) Pac
Engine Bleed Air System2 Con itione Ser ice Engine BleedAirSystem Fuel Tan Inertin S stem Air S stem (ATA 21) pneumatic EBAS Full X X X Protection S stem
(ATA 47)
Win Ice
(ATA 30)
pneumatic
Electro- EBAS
X
05 FAST#61 06 FAST#61 troubleshooting tasksshouldbeappliedwhenafaultistriggered. considered aspartofatroubleshootingsolutionfollowingfailure. Dedicated However, itisimportanttohighlightthattheEngineBleedCheck shouldnotbe verification, onlyforittobereturnedasNoFaultFound. offered bythecheckavoidsneedlesslyremovingandsending equipmentfor removed fortestinginshopwillbeconfirmedfaulty.Thedegree ofprecision Additionally, thesethresholdsarealsodefinedsothatanyequipment thatis function andthenschedulethecorrectiveactionnecessaryto redressthedrifts. In addition,dedicatedthresholdshavebeenidentifiedtodetectdriftineach sub‑system functionswhileavoidingtheremovalofcomponents. test portsandthedeactivationscrewofvalves,todefined Aircraft MaintenanceManual.Eachprocedurehasbeendesignedtouseonly The proceduresusedtoperformthesetestshavebeenimplementedinthe • PressureControl • PressureRegulation • TemperatureControl The checkteststhethreemainfunctionsofEngineBleedAirSystem: based onincidentreportingprovidedtoAirbusfromcustomerworkshops. together todefinerelevanttestsandcriteriaatsystemequipmentlevel, and thenontheA330ceoA340basic.AirbusLiebherrworkedclosely This preventivemaintenancewasfirstintroducedin2012ontheA320ceo, this solution,itwastestedonboththeA320ceoandA330ceo. preventive maintenanceprogrammewascreated.Tovalidatetheefficiencyof in thesystem’sfunctionsbeforeafaultistriggered.TheEngineBleedCheck manufacturers) developedapreventivemaintenanceprogrammetodetectdrift Based ontheaboverequirements,AirbusandLiebherr(valvesupplierforengine Finding thesolution:EngineBleedCheck and toinvolveonlylimitedinvestmentbyairlines. required toaddressallAirbusaircraftfittedwithfullpneumaticBleed AirSystems preventive maintenanceontheEngineBleedAirSystem.Theprogrammewas aircraft. Thisdiscussioninvolvedairlineswhoexpectedtohavededicated the creationofadedicatedFAIR(seeinsert)workinggroupforsingleaisle aircraft wasfirstdiscussedseveralyearsago,betweenairlinesandAirbus,with Preventive maintenanceforthefullpneumaticBleedAirSystemonA320ceo component ageing. was requiredtocounter-balanceperformancedegradationduebleed However, giventheimpactofbleedsystemsonoperationalreliability, asolution systems usedonearlygenerationfamilies(A320ceo,A330ceoandA340basic). Initially, designimprovementswereintroducedonthefullpneumaticbleed turn-back ordiversionduetolossofcabinpressurisationcapability. associated operationalinterruptions,aswelltosevereeventssuchin-flight Engine BleedAirSystemfailurescanleadtounscheduledmaintenancewith Defining theneed Engine BleedAirSystem
operational unexpected helps prevent Bleed Check The Engine maintenance scheduled and enabling initial deviations by detecting incidents and providesdevelopmentupdates. Airbus regularlyscreenstheitem discussion withotherairlines. issue, itpostsanewitemforfurther If anairlineisaffectedbyaspecific topics. share theirexperienceondedicated Interactive Resolution Airbus’ FAIR
Forum withAirlinesfor
, whereairlines
PN 98L36103002000 the AirbusSparesportalforcustomers. Both AirbusandLiebherrsets are availablethrough Bleed Check. shows allthetoolsnecessaryto implementtheEngine also necessarytoperformtests.Thetabletheright Test Sets.Inadditiontothese,severaladaptorsare designed tobeappliedusingthetwoproposedBleed A330ceo andA340,AMMprocedureshavebeen Liebherr. ThetoolsarethesameforA320ceo, one suppliedbyAirbusandtheother Two troubleshootingBleedTestSetsareproposed, used for troubleshooting. for thecheck isBleedTestSetthatalready limited. Withthisinmind,themaintoolrequired implement thispreventivemaintenancehadtobe As stipulatedbytheairlines,theirinvestmentto this preventiveaction? What toolsareneededtoperform kit forEngineBleedCheck Airbus BleedTestSetandassociated SBE2213
tester Sense line Test Port Universal Liebherr set kit Bleed Test Liebherr set Bleed Test Temperature control PN 98L36103002000 Airbus set Pressure regulation SBE2213 PN M82000678 Pressure control A340 basics:99127-251 A330 Family:99127-241 A320 Family:99127-231 Engine BleedAirSystem Lieb err set PN M82000678 PN 99127B03
07 FAST#61 08 FAST#61 through AMMtasksthatarequotedinthebelowtables: All proceduresfortheA320ceo,A330ceoandA340basicarealreadyavailable What proceduresareavailable? The timerequiredtoperformonetaskisapproximatelytwomanhours. implement theEngineBleedCheckdependingontheirexperience. than performingthefullsetoftestsonallengines.Thisadaptabilityallowsairlinesto They allowairlinestoperformonetestofagivenfunctionandonengine,rather In addition,procedureshavebeendesignedtobeasadaptablepossible. System OI drivers. interval canbeadaptedbyeachairlinedependingontheirkeyEngineBleedAir aircraft andtheA340basic,20monthsforA320ceoFamilyaircraft.However,this the typicalintervalforEngineBleedChecksshouldbe18monthsA330ceoFamily (Operational Interruptionmaindrivers)andcomponentsexperience(MTBUR/MTBF*), Based onaworldwidefleetstudytakingintoaccountbothexperience How oftenshouldtestsbeperformed? Engine BleedAirSystem re ulation Pressure Control Temperature control Pressure A320 A340 A330 RR A330 PW A330 GE A320 A340 A330 RR A330 PW A330 GE A320 A340 A330 RR A330 PW A330 GE 3 -11-00- 20-80 -A 3 -11-00- 20-822-A 3 -11-00- 20-81 -A 3 -11-00- 20-814-A 3 -11-00- 20-811-A 3 -11-00- 20-804-A 3 -11-00- 20-823-A 3 -11-00- 20-81 -A 3 -11-00- 20-813-A 3 -11-00- 20-810-A 3 -11-00- 20-802-A 3 -11-00- 20-821-A 3 -11-00- 20-815-A 3 -11-00- 20-812-A 3 -11-00- 20-809-A Lieb err BleedTestset AMM taskref.using Lieb err BleedTestset AMM taskref.using Lieb err BleedTestset AMM taskref.using * MTBF MTBUR MeanTimeBetweenFailures MeanTimeBetweenUnscheduledRemovals 3 -11-00- 20-80 -A01 3 -11-00- 20-822-A01 3 -11-00- 20-81 -A01 3 -11-00- 20-814-A01 3 -11-00- 20-811-A01 3 -11-00- 20-804-A01 3 -11-00- 20-823-A01 3 -11-00- 20-81 -A01 3 -11-00- 20-813-A01 3 -11-00- 20-810-A01 3 -11-00- 20-802-A01 3 -11-00- 20-821-A01 3 -11-00- 20-815-A01 3 -11-00- 20-812-A01 3 -11-00- 20-809-A01 Airbus BleedTestset AMM taskref.using Airbus BleedTestset AMM taskref.using Airbus BleedTestset AMM taskref.using
Engine Bleed Air System
Recommendations in case of findings If the check detects a drift from the dedicated thresholds of each function, additional tests may be required to determine the root cause. Correcting this drift is advised to ensure system operations until the next check. The suspected component may be replaced immediately or at the next opportunity. AMM Aircraft Maintenance Manual BMC Bleed air Monitoring Computer Findings resulting from the check are not subject to immediate troubleshooting prior to CMM Component Maintenance Manual dispatch. Operational considerations remain linked to the BMC monitoring logics ECAM Electronic Centralised Aircraft Monitor (ECAM warning, maintenance status) and associated MMEL/TSM coverage. MMEL Master Minimum Equipment List Based on the above, component removal can be scheduled at a later convenience TSM Trouble Shooting Manual while monitoring the system’s drift through Class 3** messages.
** Class 3 messages are of low urgency Finally, components that are removed during this preventive maintenance programme Class 2 messages should be dealt should be sent for CMM test & repair. It is highly recommended to tag the reason for with within 800 Flight Hours removal as “check removal” and to mention the paragraph of the AMM failure. Class 1 messages are urgent, Supplying this information will ensure the correct reason for removal and will help possibly NoGo, AOG determine the appropriate repair of the component before return into service.
Engine Bleed Check workshop To implement the Engine Bleed Check, customers can sign up for a workshop, in the Engineering Workshop portfolio in the AirbusWorld Customer Services e-catalogue. This workshop comprises: • Classroom sessions to review how the Engine Bleed Air System works • A specific review of Operational Interruptions experienced by the airlines and how to troubleshoot them • Demonstrations on an aircraft, of how the Engine Bleed Check procedures should be applied and the aim of each test done during the Bleed Check Several airlines have already benefited from this service, finding it useful and efficient, enabling them to reinforce their knowledge of the bleed air system and of preventive actions to reduce the number of Operational Interruptions.
CONCLUSION
The Engine Bleed Check is a preventive maintenance programme for the A320ceo, A330ceo and A340 basic. It assesses the robustness of the full pneumatic Engine Bleed Air System by detecting any drift of the main system functions before failure. It allows airlines to schedule engine bleed air maintenance and to increase operational reliability of the system. This solution has been implemented through AMM tasks and uses existing tools. Tasks can be carried out during scheduled checks and the intervals proposed by Airbus can be adapted depending on the airline’s experience. Performing each task takes around two man hours. The efficiency of this solution has been proven, and feedback received from airlines indicates that the operational reliability of Engine Bleed Air Systems has considerably improved, and is no longer a major concern since the introduction of this preventive maintenance. Finally, to support airlines in Engine Bleed Air System Check implementation, Airbus has deployed an engineering workshop including a demonstration on an aircraft.
For more information related to this workshop contact [email protected]. FAST#61 09 10 FAST#61 New technologyfornewaircraft repair bonded composite A350 XWB on-site, andbringthe exteriorskinoftheaircraftbacktoitsoriginal flushfinish. The solutionhadtorestore therequiredstructuralcapabilities, becarriedout without removingthem fromtheaircraftandwithminimalgrounding time. non-pressurised areas. Thenewchallengewastorepairprimary structures components. Mostoftheaffectedpartswere removableandlocatedin Over thelasttwodecades,genericsolutions wereusedfordamagedcomposite new composite-specificrepairsolutions. non-removable parts,isdrivingthedevelopment andtheindustrialisationof Fibre ReinforcedPlastic(CFRP)ontheA350 XWB andespeciallyonprimary Even ifcompositerepairsarenotnewat Airbus, theextensiveuseofCarbon [email protected] AIRBUS Embodiment IndustrialManager Sébastien DUPOUY [email protected] AIRBUS Embodiment IndustrialManager Guillaume FERRER [email protected] AIRBUS Embodiment IndustrialManager Sébastien Article by(lefttoright) HANSER
(See articleinFAST#57) assessment processesandprovenrepairsolutions. benefits suchasincreasedresistancetoimpacts,simplifieddamage (less weightfortherequiredstructuralrobustness),butalsobringing aluminium inaircraftdesignoverthepastyears,improvingperformance Fibre ReinforcedPlastic(CFRP).Thiscompositehasprogressivelyreplaced The primarystructureoftheA350 XWB(ExtraWideBody)isCarbon What isCFRP? A complexrepair, mixing bolted and bonded techniques
a permanentrepair. to bereplacedby (external doubler)has non-flush repair this efficientbutvisible period (lifelimitation), and safely.Afteragrace service veryquickly the aircraftbackto AOG situation,bringing This willcertainlyfixan doubler bolted metallic Quick buttemporary techniques availablegivedifferentaerodynamicandaestheticfinishes: The maindriversarealwayssafetyandleadtime.threecompositerepair Adapting therepairtypetosituation and expectations,inaccordancewithairworthinessconditions. structure. Bondedrepairisadaptedtocustomers’specificrequirements scenarios, basedonthenewrequirementspresentedbyA350 XWB to adviseonthemostappropriatesolutionspecificdamageandrepair Airbus usesitswideexperienceinbuildingandrepairingcompositestructures then ametallicboltedsolutionorbondedrepairarethepreferredmethods. requirements ofthedamagedarea:ifdamageaffectsstructuralelements, principle isusedtoselectthechoiceofrepairsolutiondependingonstress most advancedout-of-autoclave,on-wing,bondedrepair.The‘best-fitrepair’ Different repairsolutionsexist,fromthetraditionalboltedmetallicdoubler,to Combining legacyandadvancedinnovativesolutions
dynamic consideration. cosmetic oraero- without anyadditional pre-cured CFRPdoubler This isapermanent (but notflush) CFRP repair bolted pre-cured Permanent
A350 XWBcompositebondedrepair with aflushfinish. enabling on-siterepair bonded method, repaired usingthe impacts, canbe lightning strikesorGSE damage, suchassevere experienced in-service Most commonly bonded flushrepair Permanent
11 FAST#61 12 FAST#61 A bondedrepair…fromstarttofinish A350 XWBcompositebondedrepair 1) machining. avoids plydelamination thatcanoccurwithother methodsof temperature isnotelevated,while thehighprecisionofjet water meansthatnocarbondust isgenerated,andthat The RepairJet®allowscleanand safemachining;thepressurised ply numbers). the designengineeringrequirements (tolerances,orientations, Sand-stepping requiresahighlevelofexperiencetomatch (consistent depthmachining). speed, nozzledesign,mediatype…)toobtainthefinalresult This processcombinesaprecisesetofparameters(pressure, perform (lowershells,overheadworking). situation andergonomicsmakeitdifficultoruncomfortableto Repair Jet®allowsittobeusedinareaswheretherepair’s water thatcontainsanabrasivemedia.Theportabilityofthe developed andqualifiedfortheA350 XWB,usespressurised The RepairJet®.system,whichhasbeenspecially progressively sand-steppedorremovedusinganewsystem: The areainwhichthebondedrepairistobeapplied Stepping designforbondedrepair high-speed, diamond-coatedcutter. The damagedareaisremovedbycuttingtheCFRPskinusinga removes damagedplies(layers)followingaveryprecisepattern. Once therepairdefinitionisestablished,workingpartyteam Damage removal solution. with engineeringteamsanddefiningafastsaferepair This assessmentstageisessentialforcommunicatingprecisely NDT methods). array. (seeFAST57formoreinformationonCFRPdamageand mainly ultrasonicdetectionsuchasA-ScanandC-Scanphased composite –seeglossary),theNDTmeansthatareused As thefuselageskinisamonolithicstructure(asolidlaminate identification, localisationandcharacterisationofthedamage. Line tool,sizingormappingtools.Theseenableclear developed foroperationalrepairontheA350 XWBsuchas Specific Non-DestructiveTesting(NDT)equipmenthasbeen report. assessment iscarriedout,describedandrecordedinadamage Before anyengineeringdecisionorrepairaction,averyprecise Damage assessment 3) 2)
homogeneity oftherepairzonecurecyclebycontrolling To securethefinalcuringcycle,thermalprofiledefines Thermal profile 6) vacuum bagthermalinsulation. This taskisadry-runforcuring,whichvalidatesthequalityof thermal mappingofthedummyanditsrelevantbondingline. bonding. Thisdummyisequippedwiththermo-couplestorecord in therepairarea,usingareleasefilmtoavoiddummyfrom A dummypatch(representativeoftherepairpatch)isthenplaced thermo-couples whicharelocatedattheedgeofrepairzone. roughness ofthesurfacerequiredforoptimalbonding. The aimofthistestistoensuretherequiredcleanlinessand forms acontinuousfilmonthesurfacetoberepaired. behaviour. Thecleaningoperationisrepeateduntilthewater prepared surface(bondingarea)andcheckingitsphysical This testconsistsofapplyingasmallquantitywaterontothe The water-breaktest 5) nation thatcouldleadtomisbonding. chemically preparesthesurfaceremovingallsourcesofcontami liquids, mineraloilorwax.Usingspecificsolventstheoperator could contaminatethebondingprocesssuchasfuel,hydraulic bonding. Anaircraft’senvironmentoftenpresentselementsthat Once thesteppinghasbeencompleted,itiscleanedforoptimal Surface preparation 4) to in-servicedamage (eg.doorsurrounds can beapplied to areasthattakemorestress oraresusceptible *Another advantage ofCFRPisthatextralayers ofcomposite component orthestructure. This phaseiskeytorestorethe structuralintegrityofthe close aspossibletotherepair area. The repairkitispreparedinaclean roomwhichislocatedas transfer betweentheexistingstructureandrepairpatch. the steppedmachiningprovidessufficientoverlaptoenable load solutions. Thesearelaidoutfollowingtheoriginalorientation and associated withapre-impregnatedresindedicatedtorepair Repair plies(fibres)aregenerallysimilartotheparentstructure, depends onthecuringcycleandrequiredthickness*. impregnated fabricortapeplies;thetypeofadhesiveused (including thesteppedarea)beforepositioningpre- An adhesivefilmisplacedintothewholepreparedsurface materials andfilmadhesives Repairing withpre-impregnated 7) A350 XWBcompositebondedrepair ).
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13 FAST#61 A350 XWB composite bonded repair
8) Compaction A compaction phase is used to consolidate cohesion between the plies and to remove air bubbles before the final curing cycle. This consolidation is another important phase during the ‘out-of- autoclave’ repair process, as the repair will be submitted to less pressure than traditional ‘in-autoclave’ manufacturing or repair processes.
9) Vacuum bagging (internal/external) A vacuum bag is installed to maintain pressure on the plies during the curing cycle. In a case where damage has perforated the skin, a vacuum bag on both sides ensures vacuum communication and tightness. Auxiliary material such as vacuum bag, backing plate, breather fabric and peel plies* are defined by the Aircraft Structure Repair (ASR) instructions.
Vacuum bagging