DEPARTMENTOFTRANSPORTATIONFederalAviationAdministration14CFRPart39[DocketNo.FAA-2015-3753;DirectorateIdentifier2015-NE-26-AD]RlN2120-AA64AirworthinessDirectives;TurbomecaS.A.TurboshaftEnginesAGENCY:FederalAviationAdministration(FAA),DOT.ACTION:Noticeofproposedrulemaking(NPRM).(4910-13-P]SUMMARY:Weproposetoadoptanewairworthinessdirective(AD)forcertainTurbomecaS.A.Arriel2B,2Bl,2C,2Cl,2C2,2D,2E,2Sl,and2S2turboshaftengines.ThisproposedADwaspromptedbyareportofanuncommandedin-flightshutdownofanArriel2enginecausedbyruptureofthe41-toothgear,whichformspartofthebevelgearintheengineaccessorygearbox(AGB).ThisproposedADwouldrequireinspection,and,dependingontheresults,removaloftheengineAGB.WeareproposingthisADtopreventfailureoftheengineAGB,whichcouldleadtoin-flightshutdown,damagetotheengine,anddamagetotheaircraft.DATES:WemustreceivecommentsonthisproposedADby[INSERTDATE60DAYSAFTERDATEOFPUBLICATIONINTHEFEDERALREGISTER].ADDRESSES:Youmaysendcommentsbyanyofthefollowingmethods:•FederaleRulemakingPortal:Gotohttp://www.regulations.gov.Followtheinstructionsforsubmittingcomments.•Mail:DocketManagementFacility,U.S.DepartmentofTransportation,1200NewJerseyAvenueSE.,WestBuildingGroundFloor,RoomW12-140,Washington,DC20590-0001.•HandDelivery:DelivertoMailaddressabovebetween9a.m.and5p.m.,MondaythroughFriday,exceptFederalholidays.•Fax:202-493-2251.ForserviceinfmmationidentifiedinthisproposedAD,contactTurbomecaS.A.,40220Tarnos,France;phone:330559744000;fax:330559744515.YoumayviewthisserviceinformationattheFAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA.ForinformationontheavailabilityofthismaterialattheFAA,call781-238-7125.ExaminingtheADDocketYoumayexaminetheADdocketontheInternetathttp://www.regulations.govbysearchingforandlocatingDocketNo.FAA-2015-3753;orinpersonattheDocketOperationsofficebetween9a.m.and5p.m.,MondaythroughFriday,exceptFederalholidays.TheADdocketcontainsthisproposedAD,themandatorycontinuingairworthinessinformation(MCAI),theregulatoryevaluation,anycommentsreceived,andotherinformation.TheaddressfortheDocketOffice(phone:800-647-5527)isintheADDRESSESsection.CommentswillbeavailableintheADdocketshortlyafterreceipt.FORFURTHERINFORMATIONCONTACT:PhilipHaberlen,AerospaceEngineer,EngineCertificationOffice,FAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA01803;phone:781-238-7770;fax:781-238-7199;email:philip.haberlen@faa.gov.2SUPPLEMENTARYINFORMATION:CommentsInvitedWeinviteyoutosendanywrittenrelevantdata,views,orargumentsaboutthisproposedAD.SendyourcommentstoanaddresslistedundertheADDRESSESsection.Include"DocketNo.FAA-2015-3753;DirectorateIdentifier2015-NE-26-AD"atthebeginningofyourcomments.Wespecificallyinvitecommentsontheoverallregulatory,economic,environmental,andenergyaspectsofthisproposedAD.WewillconsiderallcommentsreceivedbytheclosingdateandmayamendthisproposedADbasedonthosecomments.Wewillpostallcommentswereceive,withoutchange,tohttp://www.regulations.gov,includinganypersonalinfom1ationyouprovide.WewillalsopostareportsummarizingeachsubstantiveverbalcontactwithFAApersonnelconcerningthisproposedAD.DiscussionTheEuropeanAviationSafetyAgency(EASA),whichistheTechnicalAgentfortheMemberStatesoftheEuropeanCommunity,hasissuedEASAAD2015-0162,datedAugust6,2015(refen·edtohereinafteras"theMCAI''),tocorrectanunsafeconditionforthespecifiedproducts.TheMCAIstates:Anuncommandedin-flightshut-down(IFSD)ofanARRIEL2enginewasreported,causedbyruptureofthe41-toothgear,whichformspartofthebevelgearoftheaccessorygearbox(moduleMOl).Thesubsequentinvestigationrevealedthatwearonthehousingofthefrontbearingofthisgearwasamajorcontributortothisrupture.Inaddition,theinvestigationshowedthatthiswearmechanismhadresultedinpositiveSpectrometricOilAnalysis(SOA)indicationsbeforetheevent.3Thiscondition,ifnotdetectedandcorrected,couldpotentiallyleadtofurthercasesofIFSD,possiblyresultinginanemergencylanding.YoumayobtainfurtherinformationbyexaminingtheMCAIintheADdocketontheInternetathttp://www.regulations.govbysearchingforandlocatingDocketNo.FAA-2015-3753.RelatedServiceInformationunder 1CFRPart51TurbomecaS.A.hasissuedMandatoryServiceBulletinNo.292722861,VersionA,datedApril24,2015.TheserviceinformationdescribesproceduresforinspectingtheengineAGB.ThisserviceinformationisreasonablyavailablebecausetheinterestedpartieshaveaccesstoitthroughtheirnormalcourseofbusinessorbythemeansidentifiedintheADDRESSESsectionofthisdocument.FAA'sDeterminationandRequirementsofThisProposedADThisproducthasbeenapprovedbytheaviationauthorityofFrance,andisapprovedforoperationintheUnitedStates.PursuanttoourbilateralagreementwiththeEuropeanCommunity,EASAhasnotifiedusoftheunsafeconditiondescribedintheMCAIandserviceinformationreferencedabove.WeareproposingthisADbecauseweevaluatedallinformationprovidedbyEASAanddeterminedtheunsafeconditionexistsandislikelytoexistordeveloponotherproductsofthesametypedesign.ThisproposedADwouldrequireinspection,and,dependingontheresults,removaloftheengineAGB.CostsofComplianceWeestimatethatthisproposedADaffects250enginesinstalledonaircraftofU.S.registry.Wealsoestimatethatitwouldtakeabout0.5hoursperenginetocomplywiththeinitialinspectionrequirementinthisproposedADandabout2hoursperengine4toremovetheengineAGB.Thespectrometricoilanalysiskitcostsabout$79.Theaveragelaborrateis$85perhour.Basedonthesefigures,weestimatethecostofthisproposedADonU.S.operatorstobe$72,875.AuthorityforThisRulemakingTitle49oftheUnitedStatesCodespecifiestheFAA'sauthoritytoissuerulesonaviationsafety.Subtitle1,section106,describestheauthorityoftheFAAAdministrator."SubtitleVII:AviationPrograms,"describesinmoredetailthescopeoftheAgency'sauthority.Weareissuingthisrulemakingundertheauthoritydescribedin"SubtitleVll,PartA,SubpartIII,Section44701:Generalrequirements."Underthatsection,CongresschargestheFAAwithpromotingsafeflightofcivilaircraftinaircommercebyprescribingregulationsforpractices,methods,andprocedurestheAdministratorfindsnecessaryforsafetyinaircommerce.Thisregulationiswithinthescopeofthatauthoritybecauseitaddressesanunsafeconditionthatislikelytoexistordeveloponproductsidentifiedinthisrulemakingaction.RegulatoryFindingsWedeterminedthatthisproposedADwouldnothavefederalismimplicationsunderExecutiveOrder13132.ThisproposedADwouldnothaveasubstantialdirecteffectontheStates,ontherelationshipbetweenthenationalGovernmentand theStates,oronthedistributionofpowerandresponsibilitiesamongthevariouslevelsofgovemment.Forthereasonsdiscussedabove,Icertifythisproposedregulation:(1)Isnota"significantregulatoryaction"underExecutiveOrder12866,5(2)Isnota"significantrule"undertheDOTRegulatoryPoliciesandProcedures(44FR11034,February26,1979),(3)WillnotaffectintrastateaviationinAlaskatotheextentthatitjustifiesmakingaregulatorydistinction,and(4)Willnothaveasignificanteconomicimpact,positiveornegative,onasubstantialnumberofsmallentitiesunderthecriteriaoftheRegulatoryFlexibilityAct.ListofSubjectsin14CFRPart39Airtransportation,Aircraft,Aviationsafety,Incorporationbyreference,Safety.TheProposedAmendmentAccordingly,undertheauthoritydelegatedtomebytheAdministrator,theFAAproposestoamend14CFRpart39asfollows:PART39-AIRWORTHINESSDIRECTIVES1.Theauthoritycitationforpart39continuestoreadasfollows:Authority:49U.S.C.106(g),40113,44701.§39.13!Amended]2.TheFAAamends§39.13byaddingthefollowingnewairworthinessdirective(AD):TurbomecaS.A.:DocketNo.FAA-2015-3753;DirectorateIdentifier2015-NE-26-AD.(a)CommentsDueDateWemustreceivecommentsby[INSERTDATE60DAYSAFTERDATEOFPUBLICATIONINTHEFEDERALREGISTER].(b)AffectedADsNone.6(c)ApplicabilityThisADappliestoTurbomecaS.A.Arriel2B,2B1,2C,2C1,2C2,2D,2E,2S1,and2S2turboshaftengineswithanengineaccessorygearbox(AGB),partnumber0292120650,withamachinedfrontcasing.(d)ReasonThisADwaspromptedbyareportofanuncommandedin-flightshutdownofanArriel2enginecausedbyruptureofthe41-toothgear,whichformspartofthebevelgearintheengineAGB.WeareissuingthisADtopreventfailureoftheengineAGB,whichcouldleadtoin-flightshutdown,damagetotheengine,anddamagetotheaircraft.(c)ActionsandComplianceComplywiththisADwithinthecompliancetimesspecified,unlessalreadydone.(1)InitialSpectrometricOilAnalysis(SOA)(i)PerformaninitialSOAwithinthecompliancetimesgiveninparagraph(e)(l)(i)(A)or(e)(1)(i)(B)ofthisAD:(A)IftheengineAGBhaslessthan800enginehours(EHs)sinceneworsincelastoverhaul,doaninitialSOAbeforeexceeding850EHssinceneworsincelastoverhaul.(B)IftheengineAGBhas800EHsormoresinceneworsincelastoverhaul,oriftheEHsareunknown,doaninitialSOAwithin50EHsaftertheeffectivedateofthisAD.(C)Useparagraphs2.4.2.1and2.4.2.2ofTurbomecaS.A.MandatoryServiceBulletin(MSB)No.292722861,VersionA,datedApril24,2015,toperformtheSOArequiredbyparagraph(e)ofthisAD.7(ii)Reserved.(2)RepetitiveSOA(i)IfthealuminumconcentrationdeterminedfromthemostrecentSOAislessthan0.8partspermillion(PPM),repeattheSOArequiredbyparagraph(e)ofthisADwithin100EHstimesincelastanalysis(TSLA).(ii)IfthealuminumconcentrationdeterminedfromthemostrecentSOAisbetween0.8PPMand1.4PPM,inclusive,repeattheSOArequiredbyparagraph(e)ofthisADwithin50EHsTSLA.DonotperformdrainingbeforedoingthenextSOA.(iii)IfthealuminumconcentrationdeterminedfromthemostrecentSOAisgreaterthan1.4PPM,removetheengineAGBfromservicewithin50EHsTSLA.(f)AlternativeMethodsofCompliance(AMOCs)TheManager,EngineCertificationOffice,FAA,mayapproveAMOCsforthisAD.Usetheproceduresfoundin14CFR39.19tomakeyourrequest.Youmayemailyourrequestto:ANE-AD-AMOC@faa.gov.(g)Related Information(1)FormoreinformationaboutthisAD,contactPhilipHaberlen,AerospaceEngineer,EngineCertificationOffice,FAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA01803;phone:781-238-7770;fax:781-238-7199;email:philip.haberlen@faa.gov.(2)RefertoMCAIEuropeanAviationSafetyAgencyAD2015-0162,datedAugust6,2015,formoreinformation.YoumayexaminetheMCAIintheADdocketontheInternetathttp://www.regulations.govbysearchingforandlocatingitinDocketNo.FAA-2015-3753.8(3)TurbomecaS.A.MSBNo.292722861,VersionA,datedApril24,2015,canbeobtainedfromTurbomecaS.A.,usingthecontactinformationinparagraph(g)(4)ofthisproposedAD.(4)ForserviceinformationidentifiedinthisproposedAD,contactTurbomecaS.A.,40220Tarnos,France;phone:330559744000;fax:330559744515.(5)YoumayviewthisserviceinformationattheFAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA.ForinformationontheavailabilityofthismaterialattheFAA,call781-238-7125.IssuedinBurlington,Massachusetts,onNovember12,2015.ColleenM.D'Alessandro,DirectorateManager,Engine&PropellerDirectorate,AircraftCertificationService.9