DEPARTMENTOFTRANSPORTATIONFederalAviationAdministration14CFRPart39[DocketNo.FAA-2015-3585;DirectorateIdentifier2015-NE-22-AD)RIN2120:.AA64AinvorthinessDirectives;EngineAllianceTurbofanEnginesAGENCY:FederalAviationAdministration(FAA),DOT.ACTION:Noticeofproposedrulemaking(NPRM).[4910-13-P)SUMMARY:Weproposetoadoptanewairworthinessdirective(AD)forcertainEngineAlliance(EA)GP7270turbofanengines.ThisproposedADwaspromptedbythemanufacturerinformingusthattheinspectionandrepaircriteriainthemaintenancemanualforaftboltholesofthehigh-pressurecompressor(HPC)coneshaftontheaffectedenginesisincorrect.ThisproposedADwouldrequireinspectionoftheHPCconeshaftandrepairofaffectedparts,ifneeded.WeareproposingthisADtopreventfailureoftheHPCconeshaft,whichcouldleadtouncontainedenginefailureanddamagetotheairplane.DATES:WemustreceivecommentsonthisproposedADby(fNSERTDATE60DAYSAFTERDATEOFPUBLICATTONTNTHEFederalRegister].ADDRESSES:Youmaysendcomments,usingtheproceduresfoundin14CFR11.43and11.45,byanyofthefollowingmethods:•FederaleRulemakingPortal:Gotohttp://www.regulations.gov.Followtheinstructionsforsubmittingcomments.•Fax:202-493-2251.•Mail:U.S.DepartmentofTransportation,DocketOperations.M-30,WestBuildingGroundFloor,RoomWl2-140,1200NewJerseyAvenueSE.,Washington,DC20590.•HandDelivery:DelivertoMailaddressabovebetween9a.m.and5p.m.,MondaythroughFriday,exceptFederalholidays.ForserviceinformationidentifiedinthisproposedAD,contactEngineAlliance,400MainSt.,EastHartford,CT06108,MIS169-10,phone:800-565-0140;email:help24@pw.utc.com;website:sp.engineallianceportal.com.YoumayviewthisserviceinformationattheFAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA.ForinformationontheavailabilityofthismaterialattheFAA,call781-238-7125.ExaminingtheADDocketYoumayexaminetheADdocketontheInternetathttp://www.regulations.govbysearchingforandlocatingDocketNo.FAA-2015-3585;orinpersonattheDocketManagementFacilitybetween9a.m.and5p.m.,MondaythroughFriday,exceptFederalholidays.TheADdocketcontainsthisproposedAD,theregulatoryevaluation,anycommentsreceived,andotherinformation.ThestreetaddressfortheDocketOffice(phone:800-647-5527)isintheADDRESSESsection.CommentswillbeavailableintheADdocketshortlyafterreceipt.FORFURTHERINFORMATIONCONTACT:MartinAdler,AerospaceEngineer,Engine&PropellerDirectorate,FAA,12NewEnglandExecutivePark,Burlington,MA01803;phone:781-238-7157;fax:781-238-7199;email:martin.adler@faa.gov.SUPPLEMENTARYINFORMATION:CommentsInvitedWeinviteyoutosendanywrittenrelevantdata,views,orargumentsaboutthisproposal.SendyourcommentstoanaddresslistedundertheADDRESSESsection.Include"DocketNo.FAA-2015-3585;DirectorateIdentifier2015-NE-22-AD"atthebeginningofyourcomments.Wespecificallyinvitecommentsontheoverallregulatory,economic,environmental,andenergyaspectsofthisproposedAD.Wewillconsiderall2comments

rece

i ved

by

the closing

date

and may amend

this proposed

AD because

of those comments. We

will

post

all comments

we receive,

without

change

, to http: //www. regulations.gov,

including

any personal information

you provide.

We

will also

post

a report summarizing

each substantive

verba

l contact

we receive

about

this proposed

AD. Discussion

We learned

from

the manufacturer

that

the

in spection

criteria

and

the repair procedures

for

the

aft bolt holes

of the HPC

cone shaft,

also referr

ed

to

as the

" HPC forward

stub shaft,"

were

listed incorrectl

y

in the maintenance

manual

for

the Engine A llian

ce GP7270

tu

r bofan engines.

HPC

cone

s hafts inspected

or repaired

using

the incorrect

cr

it er

i a

in the maintenance

manual

could

result

in premature

cracking

of these parts.

This condi

ti

o

n

, if not corrected

, could

result

in failure

of the

I IP

C cone

shaft,

wh

i ch could

lead

to uncontained

engine

failure

and damage

to the

airp

l ane. Relevant

Service Information

under

1 CFR

Part

51 Engine Alliance

has issued

EA Service Bulletin

(SB)

No. EAG P?-72-329

, dated July

21, 2015;

and

EA

SB No. EAGP?-72-330,

dated

July

21, 2015.

The

SBs describe procedures

for

s hotpeening

and inspection

of the HPC

cone

shaft.

This

serv

ice information

i s reasonably

available

because

the interested

parties

have access

to

it through

their

n orma

l course

of business

or

by

the means identified

in the ADDRESSES section

of this NPRM. FAA's Determination We

are proposing

this

AD because

we evaluated

all

the relevant information

and determined

the unsafe condition

described previously

is likely

to exist

or develop

in other products

of the

sa me type design.

3ProposedADRequirementsThisproposedADwouldrequireinspectionoftheHPCconeshaftandrepairofaffectedparts,ifneeded.CostsofComplianceWeestimatethatthisproposedADaffectszeroenginesinstalledonairplanesofU.S.registry.Theaveragelaborrateis$85perhour.Basedonthesefigures,weestimatethecostofthisproposedADonU.S.operatorstobe$0.AuthorityforthisRulemakingTitle49oftheUnitedStatesCodespecifiestheFAA'sauthoritytoissuerulesonaviationsafety.SubtitleI,section106,describestheauthorityoftheFAAAdministrator.SubtitleVll:AviationPrograms,describesinmoredetailthescopeoftheAgency'sauthority.WeareissuingthisrulemakingundertheauthoritydescribedinSubtitleVIT,PartA,SubpartIII,Section44701:"Generalrequirements."Underthatsection,CongresschargestheFAAwithpromotingsafeflightofcivilaircraftinaircommercebyprescribingregulationsforpractices,methods,andprocedurestheAdministratorfindsnecessaryforsafetyinaircommerce.Thisregulationiswithinthescopeofthatauthoritybecauseitaddressesanunsafeconditionthatislikelytoexistordeveloponproductsidentifiedinthisrulemakingaction.RegulatoryFindingsWedeterminedthatthisproposedADwouldnothavefederalismimplicationsunderExecutiveOrder13132.ThisproposedADwouldnothaveasubstantialdirecteffectontheStates,ontherelationshipbetweenthenationalGovernmentandtheStates,oronthedistributionofpowerandresponsibilitiesamongthevariouslevelsofgovernment.Forthereasonsdiscussedabove,Icertifythisproposedregulation:4(1)Isnota"significantregulatoryaction"underExecutiveOrder12866,(2)Isnota"significantrule"undertheDOTRegulatoryPoliciesandProcedures(44FR11034,February26,1979),(3)WillnotaffectintrastateaviationinAlaskatotheextentthatitjustifiesmakingaregulatorydistinction,and(4)Willnothaveasignificanteconomicimpact,positiveornegative,onasubstantialnumberofsmallentitiesunderthecriteriaoftheRegulatoryFlexibilityAct.ListofSubjectsin14CFRPart39Airtransportation,Aircraft,Aviationsafety,Incorporationbyreference,Safety.TheProposedAmendmentAccordingly,undertheauthoritydelegatedtomebytheAdministrator,theFAAproposestoamend14CFRpart39asfollows:PART39-AIRWORTffiNESSDIRECTIVES1.Theauthoritycitationforpart39continuestoreadasfollows:Authority:49U.S.C.106(g),40113,44701.§39.13[Amended]2.TheFAAamends§39.13byaddingthefollowingnewairworthinessdirective(AD):EngineAlliance:DocketNo.FAA-2015-3585;DirectorateIdentifier2015-NE-22-AD.(a)CommentsDueDateWemustreceivecommentsby[INSERTDATE60DAYSAFTERDATEOFPUBLICATIONINTHEFederalRegister].(b)AffectedADsNone.5(c)ApplicabilityThisADappliestoEngineAlliance(EA)GP7270turbofanengineswithahighpressurecompressor(HPC)coneshaft,partnumber(PIN)382-100-907-0,installed.(d)UnsafeConditionThisADwaspromptedbythemanufacturerinformingusthattheinspectionandrepaircriteriainthemaintenancemanualforaftboltholesoftheHPCconeshaftontheaffectedenginesisincon-ect.WeareissuingthisADtopreventfailureoftheHPCconeshaft,whichcouldleadtouncontainedenginefailureanddamagetotheairplane.(e)ComplianceComplywiththisADwithinthecompliancetimesspecified,unlessalreadydone.(1)ForHPCconeshaftswithserialnumberslistedinEAServiceBulletin(SB)No.EAGP7-72-330,datedJuly21,2015,inspecttheinnerdiameteroftheHPCconeshaftaftboltholesfornicks,dents,andscratchesbeforeaccumulating9,000cyclessincenew(CSN).DonotreinstalltheHPCconeshaftiftheaftboltholehasanick,dent,orscratchthatisgreaterthan0.002inchesindepth.(2)ForHPCconeshaftswithserialnumberslistedinEASBNo.EAGP7-72-329,datedJuly21,2015,shotpeentheHPCconeshaftaftboltholesbeforeaccumulating9,000CSN.Useparagraph1oftheAccomplishmentInstructionsinEASBNo.EAGP7-72-329todotheshotpeening.(f)InstallationProhibitionAftertheeffectivedateofthisAD,donotinstallanHPCconeshaftontoanenginewiththefollowing:(1)anick,dent,orscratchinanHPCconeshaftaftboltholethatisgreaterthan0.002inchesindepth;or(2)anyrepairofanHPCconeshaftaftboltholethatdidnotincludeshotpeening.6(g)AlternativeMethodsofCompliance(AMOCs)TheManager,EngineCertificationOffice,mayapproveAMOCsforthisAD.Usetheproceduresfoundin14CFR39.19tomakeyourrequest.Youmayemailyourrequestto:ANE-AD-AMOC@faa.gov.(h)RelatedInformation(1)FormoreinformationaboutthisAD,contactMartinAdler,AerospaceEngineer,Engine&PropellerDirectorate,FAA,12NewEnglandExecutivePark,Burlington,MA01803;phone:781-238-7157;fax:781-238-7199;email:martin.adler@faa.gov.(2)EASBNo.EAGP7-72-329,datedJuly21,2015;andEASBNo.EAGP7-72-330,datedJuly21,2015,canbeobtainedfromEAusingthecontactinformationinparagraph(h)(3)ofthisproposedAD.(3)ForserviceinformationidentifiedinthisAD,contactEngineAlliance,400MainSt.,EastHartford,CT06108,MIS169-10phone:800-565-0140;email:help24@pw.utc.com;website:sp.engineallianceportal.com.(4)YoumayviewthisserviceinformationattheFAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA.ForinformationontheavailabilityofthismaterialattheFAA,call781-238-7125.IssuedinBurlington,Massachusetts,onSeptember24,2015.ColleenM.D'Alessandro,DirectorateManager,Engine&PropellerDirectorate,AircraftCertificationService.7