[4910-13-P]DEPARTMENTOFTRANSPORTATIONFederalAviationAdministration14CFRPart39[DocketNo.FAA-2015-0787;DirectorateIdentifier2015-NE-10-AD;Amendment39-18307;AD2015-22-03]R!N2120-AA64AinvorthinessDirectives;Pratt&WhitneyDivisionTurbofanEnginesAGENCY:FederalAviationAdministration(FAA),DOT.ACTION:Finalrule.SUMMARY:Weareadoptinganewairworthinessdirective(AD)forallPratt&WhitneyDivision(PW)PW4164,PW4168,PW4168A,PW4164C,PW4164C/B,PW4164-ID,PW4168-ID,PW4168A-ID,PW4170,PW4164C-ID,PW4164C/B-ID,PW4050,PW4052,PW4056,PW4060,PW4060A,PW4060C,PW4062,PW4062A,PW4152,PW4156,PW4156A,PW4158,PW4160,PW4460,PW4462,andPW4650turbofanenginesincludingmodelswitha"-3"suffixwithalow-pressureturbine(LPT)4111stageitmerairseal(lAS),partnumber(PIN)51N038,installed.ThisADwaspromptedbythediscovery,duringroutineoverhauloftheLPT,ofcracksinthebarrelsectionoftheLPT41hstagelAS.ThisADrequiresremovaloftheLPT41hstagelAS,PIN51N038,accordingtoaprescribedschedule.WeareissuingthisADtopreventfailureoftheLPT4thstagelAS,whichcouldleadtoanuncontainedIASrelease,damagetotheengine,anddamagetotheairplane.DATES:ThisADiseffective[INSERTDATE35DAYSAFTERDATEOFPUBLICATIONINTHEFEDERALREGISTER].ADDRESSES:ForserviceinformationidentifiedinthisAD,contactPratt&WhitneyDivision,400MainSt.,EastHartford,CT06108;phone:(860)565-8770;fax:(860)565-4503.YoumayviewthisserviceinformationattheFAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,:MA.ForinformationontheavailabilityofthismaterialattheFAA,call(781)238-7125.ExaminingtheADDocketYoumayexaminetheADdocketontheInternetathttp://www.regulations.govbysearchingforandlocatingDocketNo.FAA-2015-0787;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:KatherynMalatek,AerospaceEngineer,EngineCertificationOffice,FAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA01803;phone:781-238-7747;fax:781-238-7199;email:katheryn.malatek@faa.gov.SUPPLEMENTARYINFORMATION:DiscussionWeissuedanoticeofproposedrulemaking(NPRM)toamend14CFRpart39byaddinganADthatwouldapplytoallPWPW4164,PW4168,PW4168A,PW4164C,PW4164C/B,PW4164-ID,PW4168-ID,PW4168A-ID,PW4170,PW4164C-ID,PW4164C/B-1D,PW4050,PW4052,PW4056,PW4060,PW4060A,PW4060C,PW4062,PW4062A,PW4152,PW4156,PW4156A,PW4158,PW4160,PW4460,PW4462,andPW4650turbofanenginesincludingmodelswitha"-3"suffixwithanLPT41'lAS,PIN51N038,installed.TheNPRMpublishedintheFederalRegisteronJune1,2015(80FR30963).TheNPRMwaspromptedbynineoccasionsofdiscovering,duringroutineoverhauloftheLPT,cracksinthebarrelsectionoftheLPT41hstagelAS.The2NPRMproposedtorequireremovaloftheLPT4thstageIAS,PIN51N038,accordingtoaprescribedschedule.WeareissuingthisADtopreventfailureoftheLPT4thstageIAS,whichcouldleadtoanuncontainedIASrelease,damagetotheengine,anddamagetotheairplane.CommentsWegavethepublictheopportunitytoparticipateindevelopingthisAD.ThefollowingpresentsthecommentsreceivedontheNPRMandtheFAA'sresponsetoeachcomment.SupportfortheNPRMTheBoeingCompanyexpressedsupportfortheNPRM.RequesttochangeDefinitionsUnitedAirlinesandDeltaAirlinesrequestedthattheDefinitionsparagraphbechanged.UnitedAirlinesrequestedthatthedefinitionofLPToverhaulchangefrom"maintenancewhichinvolvesdisassemblyoftheLPTrotormodule"to"whentheLPTmoduleisdisassembledsufficientlytogainaccesstotheLPT4thstagerotorassembly(disk/blade/seal)."DeltaAirlinesrequestedthatthedefinitionofanLPToverhaultobedefinedas"whenalldisksintherotorareremovedfromtheengineandthebladesareremoved."WeagreethatthedefinitionofanLPToverhaulshouldbeclarified.WechangedthedefinitionofanLPToverhaulto"AnLPToverhaulisdefinedaswhenalldisksintherotorareremovedfromtheengineandthebladesareremoved."RequesttoChangeApplicabilityDeltaAirlinesrequestedchangingtheapplicabilitytoincludemodelswithanydashnumbersuffix.3Weagreewiththeintentofthisrequest.WechangedtheSummary,Discussion,andApplicabilitysectionsbyadding"...includingmodelswitha"-3"suffix..."followingthelistedenginemodelsasrequired.ConclusionWereviewedtherelevantdata,consideredthecommentsreceived,anddetermined thatairsafetyandthepublicinterestrequireadoptingthisADwiththechangesdescribedpreviously.WedeterminedthatthesechangeswillnotincreasetheeconomicburdenonanyoperatororincreasethescopeofthisAD.CostsofComplianceWeestimatethatthisADaffects72enginesinstalledonairplanesofU.S.registry.Wealsoestimatethat9oftheengineswillrequirereplacementpartsduringshopvisit,thepro-ratedcostofthesepartscostwillbe$23,805perengine,andcompliancewiththisADwillrequireabout49hoursoflaborperengine.Theaveragelaborrateis$85perhour.Wealsoestimatethat63oftheengineswillrequirereplacementpartsduringLPToverhaul,theproratedreplacementpartscostforthesepartsis$43,545perengine,andthatthese63engineswillrequire0additionalhoursoflaborperenginesincethepartsarealreadyexposedduringLPToverhaul.Basedonthesefigures,weestimatethecostofthisADonU.S.operatorstobe$2.995.065.AuthorityforthisRulemakingTitle49oftheUnitedStatesCodespecifiestheFAA'sauthoritytoissuerulesonaviationsafety.SubtitleI,section106,describestheauthorityoftheFAAAdministrator.SubtitleVII:AviationPrograms,describesinmoredetailthescopeoftheAgency'sauthority.WeareissuingthisrulemakingundertheauthoritydescribedinSubtitleVII,PartA,SubpartIII,Section44701:"Generalrequirements."Underthatsection,CongresschargestheFAAwithpromotingsafeflightofcivilaircraftinaircommerceby4prescribingregulationsforpractices,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.ListofSubjectsin14CFRPart39Airtransportation,Aircraft,Aviationsafety,Incorporationbyreference,Safety.AdoptionoftheAmendmentAccordingly,undertheauthoritydelegatedtomebytheAdministrator,theFAAamends14CFRpart39asfollows:PART39-AIRWORTHINESSDIRECTIVES1.Theauthoritycitationforpart39continuestoreadasfollows:Authority:49U,S,C,106(g),40113,4470L5

# § 39.13 [Amended] 2. The FAA amends§

39.13

by 

# adding

the following

new airworthiness

directive (AD):



# 307 **~~·;3**

**~** 

# 2015-H_..;;IE(

Pratt

& 

# Whitney

Division: Amendment

**39-18~;**



# Docket No. FAA-2015-0787;

Directorate

Identifier 2015-NE-10-AD. 

# (a) Effective

Date This

AD

is effective

[INSERT

DATE

35 DAYS AFTER

DATE

OF PUBLICATION

IN THE FEDERAL REGISTER]. (b) 

# Affected

ADs None. 

# (c) Applicability This

AD applies

to: (I)

All Pratt

& Whitney

Division

PW4164,

PW4168, PW4168A,

PW4164C, PW4164C/B,

PW4164-1D,

PW4168-1D, PW4168A-1D,

PW4170, PW4164C-1D,

and PW4164C/B-1D

turbofan

engines

with

a low-pressure

turbine

(LPT)

4th 

# stage

inner

air seal (lAS),

part number

(PIN) 51N038,

installed. (2)

All PW4050,

PW4052,

PW4056,

PW4060, PW4060A,

PW4060C,

PW4062, PW4062A,PW4152,PW4156,PW4156A,PW4158,PW4160,PW4460,PW4462,and PW4650

turbofan

engines including

models

with

a "-3" suffix

with

an LPT

4

1 h 

# stage

IAS, 

# PIN 51N038,

installed. 

# (d) Unsafe Condition This

AD

was prompted

by

the discovery, during routine

overhaul

of the LPT,

of cracks

in the barrel section

of the LPT

4

1 h 

# stage

IAS which

could,

if not corrected,

result in uncontained

lAS release,

damage

to the engine,

and damage

to the aircraft.

We

are issuing

this

AD

to prevent

failure

of the LPT

4th stage

lAS, which

could

lead

to

an uncontained

lAS release,

damage

to the engine,

and damage

to the airplane. 

# 6(e)ComplianceComplywiththisADwithinthecompliancetimesspecified,unlessalreadydone.Fortheengineslistedinparagraph(c)(!)ofthisAD:(1)AteachLPToverhaulaftertheeffectivedateofthisAD,removefromservicetheLPT4thstage!AS,PIN51N038.(2)AteachengineshopvisitaftertheeffectivedateofthisAD,removefromservicetheLPT4thstagelAS,PIN51N038,ifithasmorethan10,900cyclessincenew.(f)Installationprohibition(!)DonotinstallanyLPT4thstage!AS,PIN51N038,withmorethan0flightcyclesonanyenginelistedinparagraph( c)(1)ofthisAD.(2)Donotinstallonanyenginelistedinparagraphs(c)(2)ofthisAD,anyLPT41hstagelAS,PIN51N038,whichwaspreviouslyinstalledonanyenginelistedinparagraph(c)(!)ofthisAD.(g)DefinitionsForthepurposesofthisAD:(1)AnLPToverhaulisdefinedaswhenalldisksintherotorareremovedfromtheengineand thebladesareremoved.(2)An"engineshopvisit"istheinductionofanengineintotheshopformaintenanceinvolvingtheseparationofpairsofmajormatingengineflanges(letteredflanges).Theseparationofengineflangessolelyforthepurposeoftransportationwithoutsubsequentenginemaintenancedoesnotconstituteanengineshopvisit.(h)AlternativeMethodsofCompliance(AMOCs)TheManager,EngineCertificationOffice,FAA,mayapproveAMOCsforthisAD.Usetheproceduresfoundin14CFR39.19tomakeyourrequest.Youmayemailyourrequestto:ANE-AD-AMOC@faa.gov.7EnglandExecutivePark,Burlington,MA01803;phone:781-238-7747;fax:781-238-7199;email:katheryn.malatek@faa.gov.(j)MaterialIncorporatedbyReferenceNone.IssuedinBurlington,Massachusetts,onOctober21,2015.ColleenM.D'Alessandro,DirectorateManager,Engine&PropellerDirectorate,AircraftCertificationService.8