DEPARTMENTOFTRANSPORTATIONFederalAviationAdministration14CFRPart39[DocketNo.FAA-2015-7491;DirectorateIdentifier2015-NE-39-AD]RlN2120-AA64AirworthinessDirectives;GeneralElectricCompanyTurbofanEnginesAGENCY:FederalAviationAdministration(FAA),DOT.ACTION:Noticeofproposedrulemaking(NPRM).[4910-13-P]SUMMARY:Weproposetoadoptanewairworthinessdirective(AD)forallGeneralElectricCompany(GE)GE90-76B,GE90-77B,GE90-85B,GE90-90B,andGE90-94Bturbofanengines.ThisproposedADwaspromptedbyanuncontainedfailureofthehighpressurecompressor(HPC)stage8-10spool,leadingtoanairplanefire.ThisproposedADwouldrequireeddycurrentinspections(ECis)orultrasonicinspections(USis)oftheHPCstage8-10spoolandremovingfromservicethosepartsthatfailinspection.WeareproposingthisADtopreventfailureoftheHPCstage8-10spool,uncontainedrotorrelease,damagetotheengine,anddamagetotheairplane.DATES:WemustreceivecommentsonthisproposedADby[INSERTDATE60DAYSAFTERDATEOFPUBLICATIONINTHEFederalRegister].ADDRESSES:Youmaysendcomments,usingtheproceduresfoundin14CFR11.43and11.45,byanyofthefollowingmethods:•FederaleRulemakingPortal:Gotohttp://www.regulations.gov.Followtheinstructionsforsubmittingcomments.•Fax:202-493-2251.•Mail:U.S.DepartmentofTransportation,DocketOperations,M-30,WestBuildingGroundFloor,RoomW12-140,1200NewJerseyAvenueSE.,Washington,DC20590.•HandDelivery:DelivertoMailaddressabovebetween9a.m.and5p.m.,MondaythroughFriday,except Federalholidays.Forserviceinformationidentifiedinthisproposed-AD,contactGeneralElectricCompany,GE-Aviation,Room 285,1NeumannWay,Cincinnati,OH45215,phone:513-552-3272;fax:513-552-3329;email:geae.aoc@ge.com.YoumayviewthisserviceinformationattheFAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA.ForinformationontheavailabilityofthismaterialattheFAA,call781-238-7125.ExaminingtheADDocketYoumayexaminetheADdocketontheInternetathttp://www.regulations.govbysearchingforandlocatingDocketNo.FAA-2015-7491;orinpersonattheDocketManagementFacilitybetween9a.m.and5p.m.,MondaythroughFriday,exceptFederalholidays.TheADdocketcontainsthisproposedAD,theregulatoryevaluation,anycommentsreceived,andotherinformation.ThestreetaddressfortheDocketOffice(phone:800-647-5527)isintheADDRESSESsection.CommentswillbeavailableintheADdocketshortlyafterreceipt.FORFURTHERINFORMATIONCONTACT:JohnFrost,AerospaceEngineer,EngineCertificationOffice,FAA,12NewEnglandExecutivePark,Burlington,MA01803;phone:781-238-7756;fax:781-238-7199;email:john.frost@faa.gov.SUPPLEMENTARYINFORMATION:CommentsInvitedWeinviteyoutosendanywrittenrelevantdata,views,orargumentsaboutthisNPR1V1.SendyourcommentstoanaddresslistedundertheADDRESSESsection.2Include"DocketNo.FAA-2015-7491;DirectorateIdentifier2015-NE-39-AD"atthebeginningofyourcomments.Wespecificallyinvitecommentsontheoverallregulatory,economic,environmental,andenergyaspectsofthisNPRJ\1.WewillconsiderallcommentsreceivedbytheclosingdateandmayamendthisNPRJ\1becauseofthosecomments.Wewillpostallcommentswereceive,withoutchange,tohttp://\VWW.regulations.gov,includingany personalinformationyouprovide.WewillalsopostareportsummarizingeachsubstantiveverbalcontactwereceiveaboutthisNPRM.DiscussionWereceivedareportofanHPCstage8-10spooluncontainedfailureresultinginanairplanefire.Ongoinginvestigationshavedeterminedthatacrackinitiatedinthestage8aftwebupperfaceoftheHPC8-10spoolandpropagateduntilspoolrupture.Therootcauseofthecrackinitiationisnotyetknown.Thiscondition,ifnotcorrected,couldresultinfailureoftheHPCstage8-10spool,uncontainedrotorrelease,damagetotheengine,anddamagetotheairplane.WeareissuingthisADtocorrecttheunsafeconditionontheseproducts.RelatedServiceInformationWereviewedthefollowingchaptersofGEGE90EngineManual,GEK100700,Revision66,datedSeptember1,2015:•Chapter72-31-08,SpecialProcedure003,piece-partlevelECI,•Chapter72-00-31,SpecialProcedure006,rotorassemblyandmodulelevelECIand,•Chapter72-00-31,SpecialProcedure007,rotorassemblylevelUSL3FAA'sDeterminationWeareproposingthisNPRJv[becauseweevaluatedalltherelevantinformationanddeterminedtheunsafeconditiondescribedpreviouslyislikelytoexistordevelopinotherproductsofthesametypedesign.ProposedADRequirementsThisNPRMwouldrequireaccomplishinganECIorUSIofthestage8aftwebupperfaceoftheHPCstage8-10spoolandremovingfromservicethosepartsthatfailinspection.InterimActionWeconsiderthisproposedADinterimaction.GEisdeterminingtherootcausefortheunsafeconditionidentifiedinthisproposedAD.Oncearootcauseisidentified,wemightconsideradditionalrulemaking.CostsofComplianceWeestimatethatthisproposedADaffects54enginesinstalled01:1airplanesofU.S.registry.Wealsoestimatethatitwilltakeabout7hoursperenginetocomplywiththisAD.Theaveragelaborrateis$85perhour.Weestimateonepartwillfailinspectionatacostof$780,000.Basedonthesefigures,weestimatethetotalcostoftheADtoU.S.operatorstobe$812,130.AuthorityforthisRulemakingTitle49oftheUnitedStatesCodespecifiestheFAA'sauthoritytoissuerulesonaviationsafety.SubtitleI,section106,describestheauthorityoftheFAAAdministrator.SubtitleVII:AviationPrograms,describesinmoredetailthescopeoftheAgency'sauthority.WeareissuingthisrulemakingundertheauthoritydescribedinSubtitleVII,PartA,SubpartIII,Section44701:"Generalrequirements."Underthatsection,CongresschargestheFAAwithpromotingsafeflightofcivilaircraftinaircommerceby4prescribingregulationsforpractices,methods,andprocedurestheAdministratorfindsnecessaryforsafetyinaircommerce.Thisregulationiswithinthescopeofthatauthoritybecauseitaddressesanunsafeconditionthatislikelytoexistordeveloponproductsidentifiedinthisrulemakingaction.RegulatoryFindingsWedetenninedthatthisproposedADwouldnothavefederalismimplicationsunderExecutiveOrder13132.ThisproposedADwouldnothaveasubstantialdirecteffectontheStates,ontherelationshipbetweenthenationalGovernmentandtheStates,oronthedistributionofpowerandresponsibilitiesamongthevariouslevelsofgovernment.Forthereasonsdiscussedabove,Icertifythisproposedregulation:(1)Isnota"significantregulatoryaction"underExecutiveOrder12866,(2)Isnota"significantrule"undertheDOTRegulatoryPoliciesandProcedures(44FR11034,February26,1979),(3)WillnotaffectintrastateaviationinAlaska,and(4)Willnothaveasignificanteconomicimpact,positiveornegative,onasubstantialnumberofsmallentitiesunderthecriteriaoftheRegulatoryFlexibilityAct.ListofSubjectsin14CFRPart39Airtransportation,Aircraft,Aviationsafety,Incorporationbyreference,Safety.TheProposedAmendmentAccordingly,undertheauthoritydelegatedtomebytheAdministrator,theFAAproposestoamend14CFRpart39asfollows:PART39-AIRWORTHINESSDIRECTIVES1.Theauthoritycitationforpart39continuestoreadasfollows:Authority:49U.S.C.106(g),40113,44701.5§39.13[Amended]2.TheFAAamends§39.13byaddingthefollowingnewairworthinessdirective(AD):GeneralElectricCompany:DocketNo.FAA-2015-7491;DirectorateIdentifier2015-NE-39-AD.(a)CommentsDueDateWemustreceivecommentsby[lNSERTDATE60DAYSAFTERDATEOFPUBLICATIONlNTHEFEDERALREGISTER].(b)AffectedADsNone.(c)ApplicabilityThisADappliestoGeneralElectricCompany(GE)GE90-76B,GE90-77B,GE90-85B,GE90-90B,andGE90-94Bturbofanengineswithahigh-pressurecompressor(HPC)8-10stagespool,partnumbers(PINs)1694M80G04,1844M90G01,or1844M90G02,installed.(d)UnsafeConditionThisADwaspromptedbyanuncontainedfailureoftheHPCstage8-10spooLWeareissuingthisADtopreventfailureoftheHPCstage8-10spool,uncontainedrotorrelease,damagetotheengine,anddamagetotheairplane.(e)ComplianceComplywiththisADwithinthecompliancetimesspecified,unlessalreadydone.(1)Performaneddycurrentinspection(ECI)orultrasonicinspection(USI)ofthestage8aftwebupperfaceoftheHPCstagespool,beforeexceeding10,500cyclessinceneworwithin500cyclesinservice,aftertheeffectivedateofthisAD,whicheveroccurslater.6(2)Ateachshopvisit,performanECIorUSIofthestage8aftwebupperfaceoftheHPCstage8-10spool.(3)RemovefromserviceanyHPCstage8-10spoolthatfailstheinspectionrequiredbyparagraphs(e)(I)and( e)(2)ofthisADandreplacethespoolwithaspooleligibleforinstallation.(f)InstallationProhibitionAftertheeffectivedateofthisAD,anHPCstage8-10spool,PINs1694M80G04,1844M90G01,and1844M90G02,isnoteligibleforinstallationintoanyengine,tmlessthespoolhaspassedanECIorUS!requiredbyparagraphs(e)(I)and( e)(2)ofthisAD.(g)DefinitionForthepurposeofthisAD,anengineshopvisitistheinductionofanengineintotheshopformaintenanceduringwhichthecompressordischargepressuresealfaceisexposed.(h)AlternativeMethodsofCompliance(AMOCs)TheManager,EngineCertificationOffice,FAA,mayapproveAMOCsforthisAD.Usetheproceduresfoundin14CFR39.19tomakeyourrequest.Youmayemailyourrequestto:ANE-AD-AMOC@faa.gov.(i)RelatedInformation(1)FormoreinformationaboutthisAD,contactJohnFrost,AerospaceEngineer,EngineCertificationOffice,FAA,12NewEnglandExecutivePark,Burlington,MA01803;phone:781-238-7756;fax:781-238-7199;email:john.frost@faa.gov.(2)GEGE90EngineManual,GEK100700,Revision66,datedSeptemberI,2015,Chapter72-31-08,SpecialProcedure003,Chapter72-00-31,SpecialProcedure006,andChapter72-00-31,SpecialProcedure007,rotorassemblylevelUSIcanbeobtainedfromGeneralElectricCompany,usingthecontactinformationinparagraph(i)(3)ofthisAD.7(3)ForserviceinformationidentifiedinthisproposedAD,contactGeneralElectricCompany,GE-Aviation,Room285,1Neumam1Way,Cincinnati,OH45215,phone:513-552-3272;fax:513-552-3329;email:geae.aoc@ge.com.(4)YoumayviewthisserviceinformationattheFAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA.ForinformationontheavailabilityofthismaterialattheFAA,call781-238-7125.IssuedinBurlington,Massachusetts,onDecember22,2015.ColleenM.D'Alessandro,DirectorateManager,Engine&PropellerDirectorate,AircraftCertificationService.8