DEPARTMENTOFTRANSPORTATIONFederalAviationAdministration14CFRPart39[4910-13-P[[DocketNo.FAA-2015-0869;DirectorateIdentifier2015-NE-11-AD;Amendment39-18296;AD2015-21-04[RlN2120-AA64AirworthinessDirectives;Pratt&WhitneyTurbofanEnginesAGENCY:FederalAviationAdministration(FAA),DOT.ACTION:Finalrule.SUMMARY:Weareadoptinganewairworthinessdirective(AD)forcertainPratt&Whitney(PW)PW4164,PW4168,PW4168A,PW4164-ID,PW4168-ID,PW4168A-ID,andPW4170turbofanengines.ThisADwaspromptedbycrackfindsinthe6thstagelow-pressureturbine(LPT)disk.ThisADrequiresremovaloftheaffected6thstageLPTdisks.WeareissuingthisADtopreventfailureofthe6thstageLPTdisk,whichcouldleadtoanuncontaineddiskrelease,damagetotheengine,anddamagetotheairplane.DATES:ThisADiseffective[INSERTDATE35DAYSAFTERDATEOFPUBLICATIONINTHEFEDERALREGISTER].TheDirectoroftheFederalRegister approvedtheincorporationbyreferenceofacertainpublicationlistedinthisADasof[INSERTDATE35DAYSAFTERDATEOFPUBLICATIONINTHEFEDERALREGISTER].ADDRESSES:ForserviceinformationidentifiedinthisAD,contactPratt&Whitney,400MainSt.,EastHartford,CT06108;phone:860-565-8770;fax:860-565-4503.YoumayviewthisserviceinformationattheFAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA.ForinformationontheavailabilityofthismaterialattheFAA,call781-238-7125.ItisalsoavailableontheInternetathttp://www.regulations.govby searchingforandlocatingDocketNo.FAA-2015-0869.ExaminingtheADDocketYoumayexaminetheADdocketontheInternetathttp://www.regulations.govbysearchingforandlocatingDocketNo.FAA-2015-0869;orinpersonattheDocketManagementFacilitybetween9a.m.and5p.m.,MondaythroughFriday,exceptFederalholidays.TheADdocketcontainsthisAD,theregulatoryevaluation,anycommentsreceived,andotherinformation.TheaddressfortheDocketOffice(phone:800-647-5527)isDocumentManagementFacility,U.S.DepartmentofTransportation,DocketOperations,M-30,WestBuildingGroundFloor,RoomW12-140,1200NewJerseyAvenueSE.,Washington,DC20590.FORFURTHERINFORMATIONCONTACT:BesianLuga,AerospaceEngineer,EngineCertificationOffice,FAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA01803;phone:781-238-7750;fax:781-238-7199;email:besian.luga@faa.gov.SUPPLEMENTARYINFORMATION:DiscussionWeissuedanoticeofproposedrulemaking(NPRM)toamend14CFRpart39byaddinganADthatwouldapplytoallPWPW4164,PW4168,PW4168A,PW4164-1D,PW4168-1D,PW4168A-1D,andPW4170turbofanengines.TheNPRMpublishedintheFederalRegisteronJune8,2015(80FR32316).TheNPRMwaspromptedbyfindingsofcracksinthe6thstageLPTdisk.TheNPRMproposedtorequireremovaloftheaffected6thstageLPTdisks.WeareissuingthisADtocorrecttheunsafeconditionontheseproducts.CommentsWegavethepublictheopportunitytoparticipateindevelopingthisAD.ThefollowingpresentsthecommentreceivedontheNPRM(80FR32316,June8,2015)andtheFAA'sresponsetothiscomment.2RequesttoClarifyDefinitionofLPTShopVisitAnindividualcornmenterrequestedthatwedefine"LPTshopvisit"morepreciselytopreventunnecessarydiscussionsregardingitsmeaning.Weagree.Werevisedthedefinitiontoread:"ForthepurposeofthisAD,an"LPTshopvisit"isdefinedastheremovalofthe6thstagediskfromtheLPTrotorandtheremovalofthebladesfromthedisk."ConclusionWereviewedtherelevantdata,consideredthecommentreceived,anddeterminedthatairsafetyandthepublicinterestrequireadoptingthisADwiththechangedescribedpreviously.RelatedServiceInformationunder1CFRPart51WereviewedPWServiceBulletin(SB)No.PW4G-100-72-252,datedNovember18,2014.TheSBprovidesalistofPW6thstageLPTdisksaffectedbythisAD.ThisserviceinformationisreasonablyavailablebecausetheinterestedpartieshaveaccesstoitthroughtheirnormalcourseofbusinessorseeADDRESSESforotherwaystoaccessthisserviceinformation.CostsofComplianceWeestimatethatthisADaffects18enginesinstalledonairplanesofU.S.registry.WealsoestimatethatnoadditionalhourswillberequiredperenginetocomplywiththisADbecausetheengineisalreadydisassembledintheshopwhenwerequiretheparttoberemoved.Theaveragelaborrateis$85perhour.Weestimatethat6engineswillrequirereplacementpartsduringanLPTshopvisit,andthattheproratedreplacementpartscostwillbe$108,800perengine.Basedonthesefigures,weestimatethecostofthisADonU.S.operatorstobe$652,800.3AuthorityforthisRulemakingTitle49oftheUnitedStatesCodespecifiestheFAA'sauthoritytoissuerulesonaviationsafety.SubtitleI,section106,describestheauthorityoftheFAAAdministrator.SubtitleVII:AviationPrograms,describesinmoredetailthescopeoftheAgency'sauthority.WeareissuingthisrulemakingundertheauthoritydescribedinSubtitleVII,PartA,SubpartIII,Section44701:"Generalrequirements."Underthatsection,CongresschargestheFAAwithpromotingsafeflightofcivilaircraftinairconnnercebyprescribingregulationsforpractices,methods,andprocedurestheAdministratorfindsnecessaryforsafetyinaircommerce.Thisregulationiswithinthescopeofthatauthoritybecauseitaddressesanunsafeconditionthatislikelytoexistordeveloponproductsidentifiedinthisrulemakingaction.RegulatoryFindingsThisADwillnothavefederalismimplicationsunderExecutiveOrder13132.ThisADwillnothaveasubstantialdirecteffectontheStates,ontherelationshipbetweenthenationalgovernmentandtheStates,oronthedistributionofpowerandresponsibilitiesamongthevariouslevelsofgovernment.Forthereasonsdiscussedabove,IcertifythatthisAD:(1)Isnota"significantregulatoryaction"underExecutiveOrder12866,(2)Isnota"significantrule"underDOTRegulatoryPoliciesandProcedures(44FR11034,February26,1979),(3)WillnotaffectintrastateaviationinAlaskatotheextentthatitjustifiesmakingaregulatorydistinction,and(4)Willnothaveasignificanteconomicimpact,positiveornegative,onasubstantialnumberofsmallentitiesunderthecriteriaoftheRegulatoryFlexibilityAct.4ListofSubjectsin14CFRPart39Airtransportation,Aircraft,Aviationsafety,Incorporationbyreference,Safety.AdoptionoftheAmendmentAccordingly,undertheauthoritydelegatedtomebytheAdministrator,theFAAamends14CFRpart39asfollows:PART39-AIRWORTHINESSDIRECTIVES1.Theauthoritycitationforpart39continuestoreadasfollows:Authority:49U.S.C.106(g),40113,44701.§39.13[Amended]2.TheFAAamends§39.13byaddingthefollowingnewairworthinessdirective(AD):2015-21-04Pratt&Whitney:Amendment39-18296;DocketNo.FAA-2015-0869;DirectorateIdentifier2015-NE-11-AD.(a)EffectiveDateThisADiseffective[INSERTDATE35DAYSAFTERDATEOFPUBLICATIONINTHEFEDERALREGISTER].(b)AffectedADsNone.(c)ApplicabilityThisADappliestoallPratt&Whitney(PW)PW4164,PW4168,PW4168A,PW4164-ID,PW4168-ID,PW4168A-ID,andPW4170turbofanengineswith6thstagepressureturbine(LPT)disks,partnumber50N886,installed.(d)UnsafeConditionIbisADwaspromptedbycrackfindsinthe6thstageLPTdisk.WeareissuingthisADtopreventfailureofthe6thstageLPTdisk,whichcouldleadtoanuncontaineddiskrelease,damagetotheengine,anddamagetotheairplane.5(e)ComplianceComplywiththisADwithinthecompliancetimesspecified,unlessalreadydone.AtthenextLPTshopvisitaftertheeffectivedateofthisAD,removefromservice6thstageLPTdiskswithserialnumberslistedintheAccomplishmentInstructions,Table1,ofPWServiceBulletinNo.PW4G-l00-72-252.datedNovember18.2014.(f)DefinitionForthepurposeofthisAD,an"LPTshopvisit"isdefinedastheremovalofthe6thstagediskfromtheLPTrotorandtheremovalofthebladesfromthedisk.(g)AlternativeMethodsofCompliance(AMOCs)TheManager,EngineCertificationOffice,FAA,mayapproveAMOCsforthisAD.Usetheproceduresfoundin14CFR39.19tomakeyourrequest.Youmayemailyourrequestto:ANE-AD-AMOC@faa.gov.(h)RelatedInformationFormoreinformationaboutthisAD,contactBesianLuga,AerospaceEngineer,EngineCertificationOffice,FAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark.Burlington.MA01803;phone:781-238-7750;fax:781-238-7199;email:besian.luga@faa.gov.(i)MaterialIncorporatedbyReference(1)TheDirectoroftheFederalRegister approvedtheincorporationbyreference(IBR)oftheserviceinformationlistedinthisparagraphunder5U.S.C.552(a)andICFRpart51.(2)YoumustusethisserviceinformationasapplicabletodotheactionsrequiredbythisAD,unlesstheADspecifiesotherwise.(3)ThefollowingserviceinformationwasapprovedforIBRon[INSERTDATE35DAYSAFTERDATEOFPUBLICATIONINTHEFEDERALREGISTER].6(i)Pratt&Whitney(PW)ServiceBulletinNo.PW4G-l00-72-252,datedNovember18,2014.(ii)Reserved.(4)ForPWserviceinformationidentifiedinthisAD,contactPratt&Whitney,400MainSt.,EastHartford,CT06108;phone:860-565-8770;fax:860-565-4503.(5)YoumayviewthisserviceinformationatFAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA.ForinformationontheavailabilityofthismaterialattheFAA,ca\1781-238-7125.(6)YoumayviewthisserviceinformationattheNationalArchivesandRecordsAdministration(NARA).ForinformationontheavailabilityofthismaterialatNARA,call202-741-6030,orgoto:http://www.archives.gov/federal-register/cfr/ibrlocations.html.IssuedinBurlington,Massachusetts,onOctober9,2015.ActingDirectorateManager,Engine&PropellerDirectorate,AircraftCertificationService.7