DEPARTMENTOFTRANSPORTATIONFederalAviationAdministration14CFRPart39[DocketNo.FAA-2006-25970;DirectorateIdentifier99-NE-12-AD]RIN2120-AA64AirworthinessDirectives;TurbomecaS.A.TurboshaftEnginesAGENCY:FederalAviationAdministration(FAA),DOT.ACTION:Noticeofproposedrulemaking(NPRM).[4910-13-P]SUMMARY:Weproposetosupersedeairworthinessdirective(AD)2006-23-17,whichappliestocertainTurbornecaS.A.TurmoIVAandIVCturboshaftengines.AD2006-23-17currentlyrequiresrepetitiveinspectionsofthecentrifugalcompressorintakewheel(inducer)bladesforcracksandcorrosion,replacementofpartsthatfailinspection,andreplacementoftheTU197standardcentrifugalcompressor.ThisproposedADwouldrequirethesameinspectionsbutatrevisedintervals,addthereplacementoftheTU215standardcentrifugalcompressor,andrequirereplacementofpartsthatfailinspection.WeareproposingthisADtopreventfailureofthecentrifugalcompressorinducer,whichcouldleadtoanuncontainedbladerelease,damagetotheengine,anddamagetotheairplane.DATES:WemustreceivecommentsonthisproposedADby[INSERTDATE60DAYSAFTERDATEOFPUBLICATIONINTHEFEDERALREGISTER].ADDRESSES:Youmaysendcomments,usingthe proceduresfoundin14CFR11.43and11.45,byanyofthefollowingmethods:•FederaleRulemakingPortal:Gotohttp://www.regulations.gov.Followtheinstructionsforsubmittingcomments.•Fax:202-493-2251.•Mail:U.S.DeparhnentofTransportation,DocketOperations,M-30,WestBuildingGroundFloor,RoomW12-140,1200NewJerseyAvenueSE.,Washington,DC20590.•HandDelivery:DelivertoMailaddressabovebetween9a.m.and5p.m.,MondaythroughFriday,exceptFederalholidays.ForserviceinformationidentifiedinthisproposedAD,contactTurbomecaS.A.,40220Tarnos,France;phone:33(0)559744000;fax:33(0)559744515.YoumayviewthisserviceinformationattheFAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA.ForinfonnationontheavailabilityofthismaterialattheFAA,call781-238-7125.ExaminingtheADDocketYoumayexaminetheADdocketontheInternetathttp://www.regulations.govbysearchingforandlocatingDocketNo.FAA-2006-25970;orinpersonattheDocketManagementFacilitybetween9a.m.and5p.m.,MondaythroughFriday,exceptFederalholidays.TheADdocketcontainsthisproposedAD,theregulatoryevaluation,anycommentsreceivedandotherinformation.ThestreetaddressfortheDocketOffice(phone:800-647-5527)isintheADDRESSESsection.CommentswillbeavailableintheADdocketshortlyafterreceipt.FORFURTHERINFORMATIONCONTACT:WegoWang,AerospaceEngineer,EngineCertificationOffice,FAA,Engine&PropellerDirectorate,12NewEnglandExecutivePark,Burlington,MA01803;phone:781-238-7134;fax:781-238-7199;email:wego.wang@faa.gov.SUPPLEMENTARYINFORMATION:CommentsInvitedWeinviteyoutosendanywrittenrelevantdata,views,orargumentsaboutthisNPRM.SendyourcommentstoanaddresslistedundertheADDRESSESsection.2Include"DocketNo.FAA-2006-25970;DirectorateIdentifier99-NE-12-AD"atthebeginningofyourcomments.Wespecificallyinvitecommentsontheoverallregulatory,economic,environmental,andenergyaspectsofthisNPRJ\t1.WewillconsiderallcommentsreceivedbytheclosingdateandmayamendthisNPRMbecauseofthosecomments.Wewillpostallcommentswereceive,withoutchange,tohttp://www.regulations.gov,includinganypersonalinformationyouprovide.WewillalsopostareportsummarizingeachsubstantiveverbalcontactwereceiveaboutthisNPRM.DiscussionOnNovember7,2006,weissuedAD2006-23-17,Amendment39-14829(71FR66664,November16,2006),("AD2006-23-17"),forallTurbomecaS.A.TurmoIVAandIVCturboshaftengines.AD2006-23-17resultedfromaTurbomecaS.A.reviewoftheengineserviceexperienceandtheirdeterminationthatmorefrequentborescopeinspections(BSis)arerequiredonenginesnotmodifiedtotheTU191,TU197,orTU224standard.AD2006-23-17requiresrepetitiveBSIandeddycurrentinspections(ECis)orultrasonicinspections(Uis)ofcentrifugalcompressorintakewheel(inducer)bladesandreplacementofpartsthatfailinspectionandreplacementoftheTU197standardcentrifugalcompressor.WeissuedAD2006-23-17topreventcentrifugalcompressorintakewheel(inducer)bladecracks,whichcanresultinenginein-flightpowerloss,engineshutdown,orforcedlanding.ActionsSinceAD2006-23-17WasIssuedSinceweissuedAD2006-23-17,acentrifugalcompressorinducerbladelossoccurredonanenginemodifiedtoTU224standard.ThisbladelosswasduetocrackscausedbyimpactscombinedwithsignificanterosionofthepartnotrelatedtotheTU224modification.TurbomecaS.A.hasrevisedtheinspectionintervalsforthecentrifugal3compressor(inducer)blades,andrequiresreplacementofpartsthatfailinspection,andreplacementoftheTU197andTU215standardcentrifugalcompressors.ThisproposedADwouldrequirerepetitiveBSis,andECisorUlsofthecentrifugalcompressorinducersatrevisedintervals,replacementofpartsthatfailinspection,andreplacementoftheTU197andTU215standardcentrifugalcompressors.RelatedServiceInformationunder1CFRPart51WereviewedTurbomecaS.A.AlertMandatoryServiceBulletin(MSB)No.A249-72-0100VersionH,datedMay21,2015.TheMSBdescribesproceduresfortheinspectionandreplacementofthecentrifugalcompressorinducerblades.ThisserviceinformationisreasonablyavailablebecausetheinterestedpartieshaveaccesstoitthroughtheirnormalcourseofbusinessorbythemeansidentifiedintheADDRESSESsectionofthisNPRM.FAA'sDeterminationWeareproposingthisNPRMbecauseweevaluatedalltherelevantinformationanddeterminedtheunsafeconditiondescribedpreviouslyislikelytoexistordevelopinotherproductsofthesametypedesign.ProposedADRequirementsThisNPRMwouldrequirerepetitiveBSis,andECisorUlsbasedontheinservicerequirementsestablishedforthevariouscentrifugalcompressorinducerstandards,replacementofpartsthatfailinspection,andreplacementoftheTU197andTU215standardcentrifugalcompressors.CostsofComplianceWeestimatethatthisproposedADaffects 36enginesinstalledonairplanesofU.S.registry.Weestimatethattwooftheseengineswillrequirecompressorreplacement.Wealsoestimatethatabout40hoursperenginearerequiredtocomplyvviththisproposedAD.Theaveragelaborrateis$85perhour.Partscostabout$40,000per4engine.Basedonthesefigures,weestimatethecostofthisproposedADonU.S.operatorstobe$202,400.AuthorityforthisRulemakingTitle49oftheUnitedStatesCodespecifiestheFAA'sauthoritytoissuerulesonaviationsafety.SubtitleI,Section106,describestheauthorityoftheFAAAdministrator.SubtitleVII,AviationPrograms,describesinmoredetailthescopeoftheAgency'sauthority.WeareissuingthisrulemakingundertheauthoritydescribedinSubtitleVII,PartA,SubpartIII,Section44701,"Generalrequirements."Underthatsection,CongresschargestheFAAwithpromotingsafeflightofcivilaircraftinaircommercebyprescribingregulationsforpractices,methods,andprocedurestheAdministratorfindsnecessaryforsafetyinaircommerce.Thisregulationiswithinthescopeofthatauthoritybecauseitaddressesanunsafeconditionthatislikelytoexistordeveloponproductsidentifiedinthisrulemakingaction..RegulatoryFindingsWehavedeterminedthatthisproposedADwouldnothavefederalismimplicationsunderExecutiveOrder13132.ThisproposedADwouldnothaveasubstantialdirecteffectontheStates,ontherelationshipbetweenthenationalGovernmentandtheStates,oronthedistributionofpowerandresponsibilitiesamongthevariouslevelsofgovernment.Forthereasonsdiscussedabove,Icertifythattheproposedregulation:(1)Isnota"significantregulatoryaction"underExecutiveOrder12866,(2)Isnota"significantrule"undertheDOTRegulatoryPoliciesandProcedures(44FRII034,February26,1979),(3)WillnotaffectintrastateaviationinAlaskatotheextentthatitjustifiesmakingaregulatorydistinction,and5(4)Willnothaveasignificanteconomic impact,positiveornegative,onasubstantialnumberofsmallentitiesunderthecriteriaoftheRegulatoryFlexibilityAct.ListofSubjectsin14CFRPart39Airtransportation,Aircraft,Aviationsafety,Incorporationbyreference,Safety.TheProposedAmendmentAccordingly,undertheauthoritydelegatedtomebytheAdministrator,theFAAproposestoamend14CFRpart39asfollows:PART39-AIRWORTHINESSDIRECTIVES1.Theauthoritycitationforpart39continuestoreadasfollows:Authority:49U.S.C.I06(g),40II3,44701.§39.13[Amended]2.TheFAAamends§39.13byremovingairworthinessdirective(AD)2006-23-I7,Amendment39-I4829(7IFR66664,NovemberI6,2006)("2006-23-IT'),andaddingthefollowingnewAD:TurbomecaS.A.:DocketNo.FAA-2006-25970;DirectorateIdentifier99-NE-12-AD.(a)CommentsDueDateTheFAAmustreceivecommentsonthisADactionby[INSERTDATE60DAYSAFTERDATEOFPUBLICATIONINTHEFEDERALREGISTER].(b)AffectedADsThisADreplacesAD2006-23-I7.(c)ApplicabilityThisADappliestoTurbomecaS.A.TunnoIVAandIVCturboshaftengines.(d)UnsafeConditionThisADwaspromptedbyacentrifugalcompressorinducerbladeloss.WeareissuingthisADtopreventfailureofthecentrifugalcompressorinducer,whichcouldleadtoanuncontainedbladerelease,damagetotheengine,anddamagetotheairplane.6

# (e) 

# Compliance Comply

with

this

AD within

the compliance

times specified,

unless already

done. ( 1) Remove

the

TU

197

and

TU

215 standard centrifugal compressors

and install the

TU

224 standard centrifugal compressor,

within

30 days

after

the effective

date

of this

AD.

(2) Perform

initial

and repetitive

ultrasonic inspections

(Uis)

or eddy current inspections

(ECis)

of the centrifugal compressor

(inducer).

Use Accomplishment Instructions,

paragraph

6.B.(l)(b) ofTurbomeca

S.A. Alert Mandatory

Service Bulletin (MSB)

No. A249

72 0100 Version

H, dated

May

21, 2015

to

do

the inspections.

Use Appendix

1 ofTurbomeca

S.A. Alert

MSB

No. A249

72 0100 Version

H, dated

May

21, 2015

for

the schedule

of inspections. (3) Perform

initial

and repetitive borescope inspections

(BSis)

of the centrifugal compressor

inducer.

Use Accomplishment

Instructions,

paragraphs

6.B.(1)(a)

of Turbomeca

S.A. Alert

MSB

No. A249

72 0100 Version

H, dated

May

21, 2015

to

do

the inspections.

Use Appendix

1 ofTurbomeca

S.A. Alert

MSB

No. A249

72 0100 Version H, dated

May 21,2015

for

the schedule

of inspections. ( 4)

If, during

any inspection

required

by paragraphs

(e)(2)

or

( e)(3)

of this

AD, any crack, corrosion,

or other damage

is detected

on the inducer,

then before

next flight, replace

the centrifugal compressor. (5) Accomplishment

of

a UI

or ECI

of the centrifugal

compressor

inducer, required

by paragraph

(e)(2)

of this

AD,

is acceptable

in lieu

of

a BSI required

by paragraph

( e)(3)

of this

AD

for that engine. ( 6) Replacement

of

a centrifugal

compressor

required

by paragraph

(e)(

4)

of this AD,

does

not constitute terminating

action

for

the repetitive inspections

required

by paragraphs

(e)(2)

and (e)(3)

of this

AD.



# 7(f) Credit

for Previous

Actions You

may

take credit

for

the inspections

and corrective

actions required

by paragraph

( e )(2)

and

( e )(3)

of this

AD

if you performed

the inspections

and corrective actions

before

the effective

date

of this

AD, using Turbomeca

S.A. Alert

MSB

No. A249 72 0100, Version

G,

or

an earlier version. (g) Alternative

Methods

of Compliance

(AMOCs) The Manager,

Engine Certific_ation

Office,

FAA,

may approve

AMOCs

for this AD.

Use

the procedures

found

in

14 CFR 39.19

to make

your request.

You

may email your request

to; ANE-AD-AMOC@faa.gov. (h) Related Information (1) For more information

about

this

AD, contact

Wego

Wang, Aerospace Engineer,

Engine Certification

Office,

FAA, Engine

& Propeller Directorate,

12 New England Executive

Park, Burlington,

MA 01803;

phone: 781-238-7134;

fax: 781-238- 7199;

email: wego.wang@faa.gov. (2) For service information

identified

in this

AD, contact Turbomeca

S.A., 40220 Tarnos,

France;

phone:

33 (0)5

59

74

40

00;

fax:

33 (0)5

59

74

45

15. (3) You

may view

this service information

at the FAA, Engine

& Propeller Directorate,

12 New England Executive

Park, Burlington,

MA.

For information

on the availability

of this material

at the FAA,

call 78!-238-7125. Issued

in Burlington, Massachusetts,

on November

x:-., 2015. Colleen

M.

D' Alessandro, Directorate

Manager,

Engine

& Propeller Directorate, Aircraft Certification

Service.

8