504314483-Fuel-Tank-Safety-Level-I-Presentation.pdf

fuel tank safety for aircraft engineers

1. 1Air CBS Training / M-013

2. Background
Harmonization Goals
Ignition Source Prevention Status
Flammability Reduction Status
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3. Fuel Tank Safety -Background
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4. SFAR 88 Lessons Learned
Goal of SFAR 88 was to preclude ignition sources
Safety Assessments were very valuable
Design reviews revealed unexpected ignition sources
Difficulty in identifying all ignition sources
Number of previously unknown failures found
Continuing threat from still unknown failures
Unrealistic to expect we can eliminate all ignition sources
Must consider flammability reduction of high flammability
tanks as an integral part of system safety
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5. SFAR 88 Lessons Learned
Abarchartcomparing
recordedtemperatures
indifferentareasofa
747centerfueltank
duringteststhatwere
performedwhenthe
tankwasnearlyempty
andabouthalffull.The
testswerecarriedout
at13,800ft,thesame
altitudeatwhichTWA
Flight800exploded
[NTSBe,1997].
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6. Balanced Approach with
Flammability Reduction
HAZARD
ACCIDENT
Ignition Prevention
Layer
-Some holes eliminated
(e.g. design changes to
preclude single failures)
-Other holes reduced in
size (human factors/
maintenance issues,
unknowns, etc.)
Flammability Layer
-Reducing flammability
exposure significantly
reduces holes
(flammability reduction)
-Small holes remain due
to system performance,
dispatch relief, system
reliability, etc.
ACCIDENT
PREVENTED
!
SFAR 88
Flammability Reduction /
Low Flammability
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7. Balanced Approach with
Flammability Reduction
Main Wing Tanks 2-4% Tail Tanks 2-4%
Body Tanks
•Un-pressurized >20%
•Pressurized <5%
Center Wing Tank with Adjacent Pack Bays 15 -20%
•Center Wing Tanks without Pack Bays 4-7%
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8. Balanced Approach with
Flammability Reduction
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9. Harmonization Goal
ToestablishmutuallyacceptablepositionsbetweentheFAA
andEASArelatedtofueltanksafety,workingwithinthe
requirementsoftheexistinganddevelopingrulesand
policies,whilerespectingtheresponsibilitiesoftheStateof
Design:
Resultinginacommon solutionsetfortheoperators,
and
Facilitatingtransferofairplanesfromcountry-to-country
withminimalimpactonoperators.
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10. Harmonization Process
FAAandEASAhaveclosedSFAR88openissues
FAAandEASAarecoordinatingcommon SFAR88
closurelettersthatwillbesenttomanufacturers
WeeklyinternalFAAteammeetingstomonitorallfueltank
safetyactivity
EASAinternalteamcoordination
BiweeklyFAA,EASAandTCCAteleconstocontinueand
reinforceharmonizationeffort
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11. Ignition Prevention Status
Ignitionpreventionsafetyreviewscompleted
Designchangeshavebeenidentified
Commonsolutionsetagreed
TCholdersarepreparingservicebulletinsand
ADsarebeingissued
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12. Ignition Prevention –
Operating Requirements
Operatingrulescompliancedatesextended
FAA/EASAhadrequiredincorporationofmaintenance
programchangesbyDecember2004
FAA noticeextended compliance date to
December2008
EASAplanstoextendoperatingrulecompliancedate
December 2005forAirworthinessLimitations(ALIs,
CDCCLs)
December2006forothermaintenanceinformation
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13. Ignition Prevention –
Operating Requirements
HarmonizedSFAR88maintenancepolicymemopublished;
EASAequivalentissued
ADsbeingissuedforsafetycriticalmaintenance
ALIs,CDCCLs
AllTCholdershavedevelopedmaintenanceinstructions
requiredbySFAR88/JAA-EASApolicy
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14. Ignition Prevention –
New Designs and Developments
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15. Flammability Reduction
Harmonization Status
FAAandEASAagreeonflammabilityreductionmeasures
fornewproductionairplanesandfuturedesigns
FAAandEASAcontinuetoworktowardcommonretrofit
position
Planagreedforworkingtowardharmonization
FAAproposedaflammabilityreductionrule
Specialconditionsareharmonized
FAAissuedfinalrule747specialconditionsJanuary24,
2005
EASAfinalizingtheirfinalrulespecialconditions
Harmonizedspecialconditionsareissuedforother
certificationprojects
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16. Summary
Balancedapproachofignitionpreventionandreduced
flammabilitycanprovideasubstantialimprovementinfuel
tanksafety
Reducingflammabilityisnowpractical
Ignitionpreventionstillmajorprotectionstrategy
Combinedstrategiesshouldvirtuallyeliminateriskof
futurefueltankexplosions
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17. Summary
FAAandEASAhavebeenworkingtoharmonizefueltank
safetyprograms
Ignitionpreventionactionsareharmonized
Significantprogressmadeinharmonizingflammability
reduction
Reachedagreementonflammabilityreduction
standardsforin-productionaircraftandnew
designs
Planagreedforworkingtowardagreementon
retrofit
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18. Summary
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19. EASA Legislation
EDDecision2007/003/R-13/03/2007
AMC66.A.45(d)Type/tasktrainingandratings.
3.Theoreticalandpracticaltrainingshouldalsotakeinto
accountcriticalaspectssuchasCriticalDesign
ConfigurationControlLimitations.
EASAguidanceisprovidedfortraininginAppendixIVto
AMCto66.A.45(d).
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20. EASA Legislation
AppendixIVtoAMCto66.A.45(d)-FuelTankSafetytraining
Thisappendixincludesgeneralinstructionsforprovidingtraining
onFuelTankSafetyissues.
1.LeveloftrainingrequiredbythisAnnexisonlylevel2.
Level2Detailedtraining
Objectives:
Theattendantshould,afterthecompletionofthetraining:
1.knowthehistoryandthetheoreticalandpracticalelements
ofthesubject,haveanoverviewofSpecialFederalAviation
Regulations(SFARs)from14CFRSFAR88oftheFAAandofJAA
TGL47,beabletogiveadetaileddescriptionoftheconceptof
CDCCL, AirworthinessLimitationsItems(ALI)andusing
theoreticalfundamentalsandspecificexamples,
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21. EASA Legislation
2.havethecapacitytocombineandapplytheseparate
elementsofknowledgeinalogicalandcomprehensive
manner.
3.havedetailedinformationonhowtheaboveitems
affecttheaircraftinthescopeoftheactivityofthe
organisationorinthefleet.
4.understandandcarryoutactivitieswiththeuseof
manufacturerandregulatoryauthoritydataproviding
instructionsondesignandmaintenance,suchasService
Bulletins,AirworthinessDirectives,AircraftMaintenance
Manual,ComponentMaintenanceManualetc.
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22. EASA Legislation
5.useeasilythemanufacturer’sdocumentationfrom
varioussourcesandapplycorrectiveactionwhere
appropriate.
6.identifythecomponentsorpartsortheaircraftsubject
toFTSfromthemanufacturer’sdocumentation,planthe
actionorapplyaServiceBulletinandanAirworthiness
Directive.
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23. EASA Legislation
Continuingtraining
Theintervalbetweencontinuingtrainingshallbe
establishedbytheorganisationemployingsuch
personnel,butshouldnotexceedtwoyears.
Thecontinuingtrainingshallincludeknowledgeon
evolutionofmaterial,tools,documentation and
manufacturer’sorcompetentauthority’sdirectives.
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24. EASA Legislation
Thetrainingforthepersonneldesignatedhastobe
carriedoutbeforeanyairworthinessreviewcertificateis
issuedoranymaintenancetaskiscertifiedonanaircraft
oracomponent.
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