### DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14 CFR Part 39 [4910-13-P]

[Docket No. FAA-2009-1100; Directorate Identifier 2009-NE-37-AD; Amendment 39-18159; AD 2014-36-0 

### ll RIN 2120-AA64 Ainvorthiness Directives; International Aero Engines AG Turbofan E n g ine s AGENCY: Fede ral Av iation Administration (FAA) , DOT. ACTION: Final rule. SUMMARY: We are supe rsedin g Ai rwo rthiness Dir ective (AD) 2012 -0 9-09 for all In ternationa l Aero Eng in es AG ( IAE) V2500-A l, V2525-D5 , and V2528-05 turbofan engines, and certain ser i al numbers (SINs) of IAE Y2522-A5, Y2524-A5, Y2527-A5 , Y2527E-A5 , V2527M-A5 , V2530-A5, and V2533

- A5 turbofan engines. AD 2012-09-09 required cl eani n g, eddy c urrent inspection (EC I) or fluorescent penetrant inspection (FPI) , and initial and repetiti ve ultrasonic in spections (USis) of certa in high-pressure compressor (HPC) stage 3 to 8 drums, as we ll as replacemen t of t h e drum a ttachme nt nuts. This new AD expands the affected population for initial and repetitive US I s of the HPC stage 3 to 8 drum , revises the inspection int ervals , requires performing ECI or fPT,
requ ir es remova l of the affected attachme nt nuts and any HPC stage 3 to 8 drum found
c racked, and adds a mandatory terminating action. Thi s AD was prompted by the discovery that additional attachment nuts for certa in H PC stage 3 to 8 drum s are affected. We are issuing thi s AD to pr event failure of the HP C stage 3 to 8 drum, wh ich could result in uncontained drum failure, damage to the eng in e, and damage to the ai rp lane. DATES: Th is AD is effective [INSER T DATE 35 D AYS AF T E R DATE OF P UB LIC A TION IN THE FEDERAL R EG I STER].The Dir ector of the Federal Register approved the incorporation by ref erence of a certain pub l ication li s ted in this AD a s of ( INSERT DAT E 35 D AYS AFTER DATE O F P UBLICAT I ON IN THE FEDERAL REGISTER]. ADDRESSES: For se rvice information identified in thi s AD, contact In ternationa l Ae ro Engines AG , 400 Main S treet, East Hartford, CT 061 1 8 ; phone: 860-368-3700 ; fax: 860- 368-4600; email: iaeinfo @ iaev2500.com ; Internet: https: //www.iaeworld.com. You may
v i

ew thi s serv i ce informatio n at the 

### f /\A , Engi n e & Propeller Directorate, 12 New England Executive Park , Burlington , MA. For information on the ava il ability of this materia l at the F AA , call 781-238-7125. 

### It is also avai lab le on the Internet at http: //www.regulations.gov by searching for and locatin g Docket No. F /\A-2009 -1 100 Examining the 

### AD Docket You may examine the AD docket on the Internet at http: //www. regulations.gov by
searchi n g for and locating Dock et No. FAA-2009-1 1 00 ; or in person at the Do cket Management Fac ili ty between 9 a.m. and 5 p.m., Mond ay through Friday , exce pt Federal h o lidays. The AD docket contains this AD , the regu latory evaluation , any comme nt s
rec e ived , and other info r mation. The address for the Docket Office (p h one: 800-647-5527) i s Document Management Facility , U.S. Department ofTransportation , Docket Operatio n s , M-30 , West Bu i lding Ground F loor , Room W 1 2-140 , 1 200 New Jersey Ave nue SE. , Was h ington , DC 20590. FOR FURTHER I NFORMATION CON TACT: Mart i n Adler, Aero s pace E ngine er , E n g in e Ce r t ifi cation Office, FAA, Engine & Prope ll er Di r ectorate, 12 New E n gland Executive Park , Burlington , MA 01803 ; phone: 781-238-7157; fax: 78 1 -238-7 199 ; email:
m a rtin .ad ler @ faa.gov.

2

### SU PP LEMEN TARY IN F O RMA TIO N: Di s cu ss ion We issued a notice of proposed rulemak ing (N PRM) to amend 14 CFR part 39 to supersede AD 2012-09-09, Amendment 39-17044 (77 FR 30371, May 23, 2012), ("AD 20 1 2-09-09 " ). AD 2012-09-09 applied to all i AE V2500-Al, V2525-D5 , and V2528-D5 turbofan engines , and certain SINs of IAE V2522-A5, V2524-A5 , V2527-A5, V2527EA5, V2527M-A5 , V2530-A5, a n d V2533-/\5 tu rbofan eng i nes. T he N P RM p u b l is h ed in the Federal Register on Dece m ber 24, 20 14 (79 FR 774 1 1 ). The NPRM was prompted by the discovery that par tially si lver-p lated nut s for certain H PC stage 3 to 8 drums cause the drum to corrode and crack. The NPRM proposed to pe r form EC I o r FP T , and initial and repetitive USIs of certain HPC stage 3 to 8 drums. T h e NPRM also proposed to expand the affected population fo r in itial and r epet it ive US Is of t h e H PC stage 3 to 8 d ru m, revise the inspect ion i nterva l s, requ ire r emoval of the affected attachment nuts and any H PC s t age 3 to 8 drum found cracked , and add a mandatory terminating action. We are issuing this AD to prevent failu re of th e HPC stage 3 to 8 drum , which cou ld res u lt in uncontained drum failure, damage to the engine, and damage to the airp lane. 

### C omm e n ts We gave the publ ic th e opportunity to pa rtic i pate in deve lop i ng th is AD. T h e follow i ng pre se nt s the comments received on the NPRM (79 FR 77411, December 24, 20 14) and the FAA's response to each comment. 

### R e que s t t o C h a n ge Co mplian ce P a ra g r a ph One commenter requested that paragraph (f)(3) of the NPRM (79 FR 774 1 1 , Dece m be r 24, 20 14) be c h a n ged from " I f you inspect th e HPC stage 3-8 dr u m at shop visit.

.. " to " If you have previously in spec ted the H PC stage 3

- 8 drum at piece-part exposure a s s hown i n th e Grace Period s Tabl e for each complianc e group listed in paragraph I.E. in IAE Alert Non-Modification Service B u llet i n (NMSB) No. V2500- 3E NG-72-A06 15 , R ev i sio n 6, dated Se ptembe r 4 , 20 14 ." T he justifica tion f o r this
co mm e n t is that the AD wording is not c lear enoug h for th e actu a l work perfo rmed. We partially ag ree. We agree wi th ref e t

T

i ng to piece-part exposure in stead of s hop v is it. We disagree with r efe rencin g the se rvi ce bulleti n (SB) because the A D wordi ng is othe rwise clear in it s re f e r

e nc e to th e G r ace P eriods Tabl e fo r eac h comp li a nce g roup. We changed paragrap h (f)(3) of thi s final rule b y changing " at shop visi t " to " at piecepart exposure." 

### Request for Pa ra g raph C l a rific ati o n T h e same co mment e r s ug ges ted adding eng in e manua l (EM) Tas k No. o r SB referenc e to p ara grap h s (g)(2), (g)(3)( i ), a nd (g)(3)( ii ) bec au se th ese para g raphs d o n ot provide the s p ec ific me th od to perform the stat ed requi r eme nt s. We do n ot agree. The SB a nd EM tasks for th ese ope ra ti o n s are not m andated. T herefo re , th ey are referenced in th e Re lated In fo rmat io n sect io n of the AD. We did not
c han ge th e A D. 

### Reque st to Clarify Te rminatin g Action Lufthan sa, Un i ted Ai rli nes (UA), and another commenter , asked that th e AD be
c larifi e d that if the terminati ng actions were p erformed prior to the effective date of the AD, credit may be taken and no fu rth e r ac ti o n wo uld be r eq uire d. T he commenter's ju sti fi cat io n is that the /\0 sho u ld be clear that if the part s are ins talled prior to effecti ve d a te of the AD , the pa rts i n s tall a ti on s ho u ld be co n s i de red as t erminatin g ac ti on . We do not agree because paragraph (e) , Compl iance , states to perform th e requirements of th e AD " un le ss a lready done. " This s tatem e nt ap p li es to a ll requirements of the AD in c lud ing th e term in ati n g act ion. No add ition a l cla rifi catio n i s nee de d

. We did
n ot change the A D
.

4

### R e qu est to C h a n ge Co mplianc e T im e An a n ony m ous commenter reque s ted th at repetit i ve in spect i ons not start u nti l after th e threshold fo r the initi al inspection ha s been reached. Th e ju s tification tor this request is that many unnecessary extra in spect ion s would have to b e performed if the initial in s pection i s performed early, and the AD requires repeat in spect ions to follow immediately. We ag r ee. This final r ul e was c h anged as fo ll ows: pa r agrap h s (f)(l) a n d (t)(2)
were changed fl·om "
... ofthe l ast USI." to "
... ofthe last USI after the i n it ia l inspection required by paragrap h (e) of this AD. " 

### Ag r ee m e n t wi t h P r op ose d A D The Boeing Company agreed with the NPRM (79 

### FR 7741 1 , December 24, 2014)
as written. 

### R e qu es t C han ge t o C o s t s of C o mplian ce Lufthansa and Wizz Air s tated that th e terminating action wi ll result in many unplanned extra s h o p visits to remov e parts. T he cost ana lysis does not include the cost associated with th ese extra shop vis i ts. We do not agree. The Costs of Comp li ance in the AD i nclude s prorated part costs based o n early remova l of parts
. Our cost ca lcu lations do n ot includ e costs associated with engine remova l , down time , or schedu l ing. We did not change th e AD. 

### R e qu es t t o Includ e R ev i s i o n a n d D a t e Inform a ti o n f o r Servi ce Inf o rm a ti o n Luft h ansa and I AE requ es ted that service information includ e r evis ion and date infor m at ion. Th ey suggested that the se rvice in f o rmation does not l ist th e l atest revision in formation or , in so me cases, any revi s ion information at a l l. We partially agree. We agree that th e SB references shou ld r e flect the latest
re vis ion. We di sag ree with adding th e revis ion and / or date to all in s tance s of SBs referenced in the Related Information paragrap h because the revi s ion date is listed on the 5fi r st instance of each S B refe r e n ced in the pa rag rap h. We c h anged the Re la t ed I nf ormatio n p a rag ra ph b y c han g in g th e da t e o fl AE NM S B No. V2500-E N G -72-06 25 to Oc to b e r 8, 20 14

. 

### Reque s t to C han ge Applicability L uftha n sa s t ated th at the compl iance categories (ap p li cab ili ty) are base d on
e n gi n e ser i a l n umber. T he commen ter s u ggested defining th e categories based o n drum
se rial numb e r ra th e r th a n e n g in e se ri a l num be r b ecau se th e in s p ec ti o n tim es an d interva ls
s h o ul d b e based o n the drum hi sto r y. T h e co rrec t in s p ecti o n tim es a n d inte r va ls m ay n ot be ut ili zed fo r th e affected dr u ms if a dr u m moves fro m one e n g ine to anot h er . We do n ot agree. We eva luated u sc o f drum serial nu m be r s versus engine serial
n um bers and chose eng i ne seria l n u mbers based on th e i n creased complexity associate d
w ith trackin g d r u m se r ia l numb ers. It was a lso no te d that it i s mo r e l ike ly th a t a n e n g ine,
as o pp ose d to a n indi v idu a l u se d d rum , wo uld be mo ve d

. Th e e n gi n e gro up s in th e A D
re fl ec t th e u nsa f e cond it io n as it ex i s t s today. lf th e engine distribut ions c h ange signi fi cant ly in th e f u tu re, we wou ld consider addition a l rulema ki ng. We did no t c h ange th e A D
. 

### Request to C han ge Service Information R o ll s R oyce p ic prop o sed th a t rev i s io n 6 of IAE A le rt NMSB N o. Y 25 00- ENG-

. 72-06 1 5 be qu oted in th e A D , a nd that a ll references to it , in c lu din g e n gi n e g ro ups affected , be al igned to th i s latest rev i s ion. T he j u st ifi catio n fo r th i s request i s th at th e
curre n t AD refere n ces IAE NMSB No. V2500-ENG

- 72

- 0615 , Revis ion 3. T his NMSB is
n ow at rev i s io n 6. We do n ot ag ree becau se th e AD a lrea d y refe re nc es R ev i s io n 6 o fl AE A lert NMSB No. V2500-ENG

- 72-A06 1 5. We d id n ot c h a n ge the AD.



### 6R eq ue st Clarification of Material Incorporated 

### by Reference UA and Delta Airlines requested clarification of whether IAE NMSB No. V2500- ENG-72-0638 is conside red incorpo rated by reference. This AD wi ll incorporate by reference IAE A le rt NMSB No. V2500-ENG 72-06 1 5, Revision 6, dated Septe mber 4, 2014 , which refers to IAE NMSB No. V2500-ENG-72-0638 for instructions on performing the US I. f AE NMSB No. V2500-ENG-72-0638 co n tains instructions and procedures that do not affect failure mode detection , prevention or e lim ination of the
un safe cond i tion id entified in th e NPRM (79 

### FR 7741 1 , December 24, 20 14 ) and shou ld not be mandated by the AD. We agree that fAE Alert NMSB No.V2500-ENG-72-0638 shou ld not be inco r porated by r efere nce. We changed th e AD to remove th e requiremen t to us e lA E NMSB No. V2500-ENG-72-0638. We also added a new paragraph (g) to thi s AD th at provides specific information from IAE NMS B No. V2500-ENG-72-0638 to perfom1 the USl. R eq u es t Change to Re l eva nt Se rv ic e Information UA and Delta Airli nes requested that l AE NMSB No. V2500-ENG-72-0638 be added to the Relevant Serv ice Information paragraph. We partially agree. We d o not ag ree with adding f AE NMSB No. V2500-ENG72-0638 to the Relevant Serv ice In formation paragraph because that paragraph is not in the final rule. We agree th at the service information shou ld be included in the AD, elsewhere. We added IAE NMSB No. V2500-ENG-72-0638 to the Related l nfonnation paragraph. R equest Clarification of Co mpli a nc e Time UA and LA TAM Airlin es requested clarifi cati on on the diff e r

ence between the AD and SB tennin at in g actions for compliance time to incorporate terminating action. The AD requ i res accomplishment within 9,450 cycles afte r the effective date of the AD , 

### 7w hil e th e S B re quir es acco mpli s hm e nt by D ece mb e r 3 1 , 2 0 2 1. Th e co mm e nte r s aid s hop v isits we re p l ann ed based o n t he en d da t e in the S B. T he A D li m it of 9 , 450 cycles wi ll force eng in es off w in g ea rli e r th a n p l an ne d

. We do not ag ree. The c yc l e limit in the AD re pr ese nts fl ee t av e r age utilizati o n up to the S B 'acco m p li s h by' date. We d id n ot chan ge the AD. 

### Request Clarification for Termin a tin g Action UA re qu ested c la rificati o n th at in s p e ction s are no t r e quire d afte r th e te rmin a tin g act io n h as b ee n p erfo rm e d. UA s u gges t e d th a t thi s cl ari f i cat io n was req ui red becau se th e SB G race Pe ri ods Tabl es includ e t im ing fo r any d rum fitted w ith non-silver n uts. It is not exp l icit th a t the table d oes not app ly to a new drum w ith n o n- s il ver nut s. W e do n ot ag ree. T e rminatin g ac tion m ea n s th a t n o furth e r act i o n is re quire d. Th ere f o re, th e AD does not require a n y a d dit ional in spect io n s after the term i na ti n g act ion has bee n acco m p li s hed. We di d not chan ge the A D
. 

### Request Deletion of Service Information UA id e ntifi ed th at IAE NMSB No. V 2 5 0 0- ENG-72-063 8 , P ar t 

### 8 paragrap h (3)Y.(3) states th at an e n g ine be rejec ted i f stai ni n g a nd/o r c rac kin g of the cera m ic l iner i s fo un d. T hi s re quire me nt s ho uld n o t be ma nd a ted b ecause thi s co nce rn was a ddressed in AD 20 1 2-09- 0 9 w hi c h w a s s up e rse ded

. T he FAA ag reed th a t the r e was n ot cl ea r accep t a nce criteria t o ma nd a te e n gi ne rejec ti o n b ased o n sta in in g an d axia l cracki n g of th e HP C s t age 7 to 8 dr um ce r a mi c l in e r . W e a g ree . We c han g ed thi s fin a l rul e b y de le tin g re f e r

e nce to l AE N MSB No

. V2500

- ENG-72-0638 in p aragrap h (e) ofthis AD. 

### Reque s t to Include a Ferry Flight UA r e qu ested th a t th e A D be c h a n ge d t o a ll ow a o ne - cycl e fe rr y fli g ht. No ju s ti fi cat io n was g ive n .



### 8We d o not agree. P e r 14 C f.R 39.23, a n A D onl y addresses fer ry flight s if the y a r e prohibit e d. We did not pro hibit ferry flig ht s in thi s AD. We did not cha n ge the AD. 

### R eque s t C larification of Compliance Time UA com m e nt ed th at some g r ace periods in AD 2012-09-09 are d i ffe re nt from th e NPRM (79 FR 77411 , December 24 , 2 0 14 ). UA r eques te d c larification th a t the o ld er compliance times i n AD 20 12-09- 09 are n o lon ge r appl icable or ava il able a nd let " Cred it for Pr ev io u s Act ion s" a llow the lo n ge r complianc e times of the NPRM. T he clarificati o n was re qu es t e d si n ce, for comp li a n ce interva ls th at h ave be e n s hortened , th e co mm e nt er can see n o way to address those engines, parti c ul a rl y if the eng in e h as a l r eady exceeded th e shortened in terva l. Fo r interval s that h ave b ee n ex tended , in spe ction inte rval s can eas il y b e ex te nded to agree . We do not agree. AD 2012-09-09 i s b e in g s uperse d e d by this AD ; therefore , th e p rev iou s co mplian ce tim es are inapp li cable after the effective date of thi s A D. This fina l rule a ll ows 200 cycles afrer the e ff ect ive date o f th e AD to perform th e initi a l USI i f th e cyc les s ince n ew thres h o ld h as be e n p assed . I f th e cy clic int e rva l a ll owed by this AD for the ne xt US I based o n th e last part in s p ec tio n ha s been surpassed , then th e ini tia l in spection r e quirem e nt s wo uld app ly. This mean s yo u mu s t in s p ec t wi thin 2 00 cycle s af

te r th e e f f e ct ive d a te of this AD. We did n ot cha n ge th e A D
. 

### Request to C han ge Se rvice Information UA stated th at the USJ pro ced ures , as defi n e d in I A E NMS B No

. V 25 00-EN G72 -0 638 , w hich lift th e probe off th e s urface of th e drum , s h ou ld not be m anda ted. The US I pro ce du res, in IAE NMSB No. Y2500-ENG-72

- 0638 , u se a " clamp " added to th e US l probe to li ft the probe off of th e drum. Thi s procedure r el ies o n coupl a nt to fi ll the ga p s to th e drum an d a ny mis s in g drum coatings. UA is not co nfid e nt tha t acc urate
m easu r e m e nt s ca n b e cons i ste ntl y achieved u si n g thi s pro ce dure, es p ec iall y in a r eas th a t h ave be e n re p aired. 

### 9We partia ll y agree. We agree that th e US I procedures in IAE NMSB No

. V2500- ENG -7 2-0638, and those r eferenced in s up e rsede d AD 2012-09-09 , a re va lid method s of insp ection. We disagree that the procedure in lA E NMSB No. V2500

- ENG-72 -0638 would not provid e acc urate me asurements. We changed this AD 

### by removing IAE NMS B No. V2500-ENG

- 72-0638 and add in g a paragraph that provides spec i fic infonnation to p erfor m the USI. 

### Request to C han ge Service Informati on Jetstar G roup Airways requested that a llo wance for f uture SB revisions b e includ ed in the AD. We do not agree. We cannot mandate doc ument s w hich do n ot ye t ex i st. We did not change th e AD. 

### Request to C han ge the Applicability Jet s tar Gro up Airways requ ested that the applicability f o r V2500-A5 e ngine s be revised to exclude En g in e Seri a l N umb er (ESN) Vl6660 a nd h igher as the introduction of the terminating action configuration began w ith ESN V 1 6660 ba se d on the applicability of IAE SB V2500-ENG-72-0632 that introduced si l ver free nuts. We do not ag r ee. Th e AD applicabi li ty i s co rrect. Th e app li cabilit y defined in IAE SB V2500-ENG-72-0632 does not r e fl ect actua l part in s tallati ons. We did not cha n ge the AD. 

### Reque st to Allow Repetitive In s p ec tion s Lufthansa, Jetstar Group A irways, Wizz Ai r , and MTU Mai nt enance (MTU) requested to re mo ve " within 9,450 cy cl es after th e effec ti ve date o f th e AD " for term ina t in g ac ti o n and a ll ow unlimi ted US I. Th e commenters pointed o ut that the un safe cond iti on result s from a co rr os ive operating env ironm e nt , and th e amo un t of corrosion varies w i th time and location. T he co mm e nters also pointed to the lack of data to support
a calen d ar e nd da te of2021, and that the hard time for p art removal s will drive you n ger 

### 10pa rt s off w in g early, w ith n o a dditio n a l be nef it s to safe ty. Fin a ll y, th e co mm e nt e r s
o ffered th a t 

### if th e US I a n d the ECI prov ide suffic ie nt sa f e ty aga in st an unconta ined fa il ure , thi s s hou ld a lso b e the case after 

### 9, 4 5 0 fli g h t cyc l es (FC)

. Add iti o n a ll y, th e ove r a ll ri s k in the fl ee t w i ll decrease due t o the nu m b e r of pl ann e d s ho p v i s it s . We do n o t ag ree. Th e o n go i ng r epet it ive i nspect io n s do n ot prov id e s uffic i e nt safe ty by the m selves a nd are cons id e red int e rim act ions. T he p revious ADs d id n ot in c lud e a n end da te becau se no termin a ti n g action was ava il a b le . Thi s A D inc lud es
m a n da to ry t e rm in a tin g ac ti o n th at comp le t e ly re m oves th e n o t e d un saf e co nditi o n a nd
res to res a n acce p table level of safety

. We did not chan ge the 

### AD. R e qu est to C h a n g e Te rmin atin g Ac ti o n Wi zz A ir , Luft h a n s a , an d D e lt a A irl in es req u es t e d th e comp l ia nce tim e f o r te rm in ati n g act io n be c h a n ged f rom 

### "9 , 450 FC after the ef f ec ti ve date of th e A D " to " at
next p iece-p art ex p osure. " T h is w ill e li m in ate ex tr a shop v is it s so lely fo r d ru m
rep lace m e nt. We d o no t ag ree. T hi s c h ange wo ul d s i gnificant ly incr ease th e need for spare par t s in the n ear ter m , which cannot be s up ported by ind u stry at t his ti me. We d i d not
c h ange th e 

### AD. R eq u es t t o Ch a n ge Co mpli a n ce IAE re qu este d th a t th e Co m pliance p hrase 

### " I f c racks are fo u nd

... " be chan ged t o

" if c r ack indic a t ions or in spect io n r ejections a re found

... "

. T he re a so n for thi s r e qu est i s th a t 

### FPl , U S l , and EC I. onl y i ndic a t e 

### a c rac k may b e pr ese nt. C r ack s typ ica ll y c a n on ly be
con fi rme d v ia lab destruct ive t est in g. We d o not agree. If a p ar t fails the in spect io n i t is assu m e d to be crac ked. No
a d d i ti o n a l test in g is r e qu es t e d o r re qu ired t o prove a c r ack ex ists . We did n ot c h an ge th e A D
.

l l

### Req ues t to C h a nge Co mp lia n ce IAE and MTU requested th at "cycles s ince new " (CSN) refer to cycles on the specific drum and not e ngine cycles since new. If drum s are replaced, th e re cou l d be
co nfu s ion on when a part must be inspected. We agree. W e changed paragraphs (e)( I) through (e)(5) from "w ithin 200 cyc les of accumulating xxxx CSN" to " within 200 cycles of the drum accumulating xxxx cycles. " 

### R eq uest to C h a n ge Co mpli an ce T im e IA E and MT U req uested an end date of Dece mber 31, 2025 be added to the compliance time in additio n to the ex istin g cyc le lim i t. Th is requ es t was justified because low utilization operators wi ll not be required to upgrad e their e n g ines until well beyond 2040 with only the cycle limit. T AE is concerned that after the large r operators hav e completed the upgrades to their fl eets, the expertise and equ i pment required to perform the required in spec tion s will no long er be ava ilable. We agree . We c hanged th e Mandatory Terminating Action paragraph to includ e an e nd date of Decemb e r 31, 2025. 

### R eq u est C h a nge to C re di t for P rev io us Ac ti o n s Parag ra ph I AE req uested that I AE NMSBs No. V2500-ENG-72-0594 , No. V 2500-ENG -72

- 0603 , No. V2500-ENG-72-0608 , Revision 2 and earlier, and No.Y2500-ENG-72-0615 , R ev ision 2 and earlier, be removed from the "C redit lor Previou s Actions " paragraph because these SB r evisions do not require complete in spection of the drum c ircumfer e nce in areas of liner loss. Incomp lete in s pection s are not effec tive at detecting c racks and compromises safety. We agree. We removed IAE NMSB No. V2500-ENG-72-0594, IA E NMSB No. Y2500-ENG-72-0603, I AE NMSB No. V2500-ENG-72-0608 , Revis ion 2 and earlier ,

12and JA E NMSB No. V2 500 -ENG-72-A0 6 15 , Rev is ion 2 and earlier , from the Credit for Previou s Act ions parag ra ph. 

### Request to Simplify Compliance Delta Ai rlin es commente d that th e comp li a nce plan a s propo se d in th e NPRM (79 FR 77411, D ece mb e r 24, 2 014), is too complicated. D e lta sa id th at it r e quires: ( I ) knowled ge of where the HPC 3-8 drum (s) have operated by flight numb er for th e Y2500- A I and V2500-A5 engi ne mod e ls; (2) track ing th e inspections p e rformed at s hop leve l for th e HP C 3-8 drum(s) ; (3) track in g the HPC m o dule asse mbl y f or the 3

- 8 drum (s) i n sta ll ed and th e co nfi g ur ation at th e la st s hop v is it of th e HPC m od ul e; and (4) operators to trace documents of HP C 3-8 drum(s) that exchanged be tween HP C modul es and f ro m o ther operators. Without those trace document s, ope rators will 

### be forced to o btain new HPC 3

- 8 drum (s) to pr eve nt rec on tamination of their r es p ec tive fl ee t s . We do not agree. The c han ges we pro p osed in thi s A D , ex p a ndin g th e popul ation , chang in g the in s pection in terva l, e tc. , are not compl e x changes to th e compliance program. We a lso eva lu ated th e original com pli ance pr ogram req uire ment s. We did not concl ud e that th ey were so complex that o perator s would find th e m difficult to und e rstand , p a rti c ula rly s in ce th e infonn at io n neede d to co mpl y w ith the AD is available in operator re co rd s. W e did not c h a nge th e AD

. 

### Request Clarification of Service Information Delta A irline s stated tha t I AE A lert NMSB No. Y2500-ENG-72-A0615 , Revis io n 6, ha s li s ts of e ng in e m ode ls and drum part numb e rs . T he S B list s drum part number s as assoc iated with the V2500 -D 5 eng ine that are not appro ved for in s tallation o n th e Y2500- D5 e n g in e. Th e SB could be mi s interpreted as a ll owing u se of part numb e rs on th e V2500-D5 engine mod el that have not actually b ee n approved for u se . We do not agree. The SB se parates eng in e ap pli cab ili ty into s ix g roups. Th e drum pa1t numb e rs li s t e d fo r eac h group represe nt the p oss ibl e drum part numb ers for all th e 1 3noted eng i ne mode ls li sted in the group. Th ese groupi ngs do not otherwise indicate tha t patt numb ers are int erchangeable among the engine mod e l s. The gro u ps th a t includ e V2500-D5 (GroupE and group F) also includ e o th er eng in e models. We did not change the AD. 

### Request C larification of Mandatory Terminatin g Action Paragraph Lufthansa requested clarification of the Mandatory Terminatin g Act io n paragraph. The commenter stated that the para gra ph directin g the installation of HP C stage 3 to 8 drum is not clear if the mandatory terminating action is meant to be a hardtime limit whic h requires removal of drums from service by means of a s hop v isit. The commenter suggested that the term in ating action fo r drum replac e ment may be substi tuted by an o n -wing US I. On-wing US I could occur after 9 ,450 

### fC from the effective date of this A D until the e ngine h as a shop visit. We do not agree. The mandatory terminating action has a hard-tim e limit of9 , 450 FC after th e effective date of this AD. The terminating actions must be performed w ithin this tim e. The AD do es not g i ve a ll owance to perfo rm insp ect i ons in p lace of pe rforming the terminat i ng actions. We did not change the AD. 

### Request to R evise Mandatory Terminating Action MTU requested that the mandatory tenninating action be de layed based on the appropriate inspection grace period li s ted in the service in formation. The grace period
ex tension wou ld elim in a te extra sho p visits for only drum repl ace ment. We do not agree. The cyclic intervals li sted in the service information , based on piece

- part inspection , app l y to th e threshold for performing the next USI. The compliance time for completing the t e rminatin g actions is not related to when or what in spect ions were performed. We did not change the AD.

14Co n c lusion W e reviewed the releva n t data, considered the co mm en t s re ceived , and d e te rmined that a ir safety and th e pub l ic i nte r est require adopt in g this AD w ith th e c h a n ges d esc rib e d previously. We h ave de term ined that these min o r chan ges: • A re consistent w ith th e intent th a t was proposed in th e NPRM 

### (79 FR 

### 7741 1 , December 

### 24 , 20 1 4) for co rrec ting the un safe con diti o n ; and
• Do not add any additional burden upon the public than was a lready propo se d in th e NPRM 

### (79 FR 

### 7741 1 , D ece mb e r 

### 24 , 20 14 ). We a l so determin e d that th ese chan ges will n o t increa se th e e conomi c burd en o n any opera tor o r increase the scope of thi s AD. 

### Costs o f Co mpli a n ce W e es timate that this AD w ill affect 

### 956 e n gi n es install ed o n airpl anes of U.S

. r eg i s try. We es timate that it will ta ke about 3 hours per e n g in e to p e rform th e US I and about 2 hours per e n g in e to p e rf o rm th e rPJ o r EC r o f th e HP C s tage 3 to 8 drum. We
a l so es tim a te that rem ov in g silver res idu e fr o m the HP C s tage 3 t o 8 drum w ill cost abo ut 

### $2 , 600 p e r e n g ine and a se t of s il ve r free nut s w ill cost about 

### $ 1 , 060 per e n gi n e. We
es tim a te the pro-rated r ep lace m e nt cost to r ep lace an HP C s ta ge 3 to 8 drum to b e 

### $52 , 014. Ba se d on th ese fi g ure s , we es timat e the cost of this AD o n U.S. ope ra tor s to be 

### $53 , 630,644. A u thori ty f o r thi s R ul c m a kin g Tit le 

### 49 of th e Un ited States Co d e s p ecifies th e FAA ' s au th ority to i ss ue rul es on aviation safety. Subtitl e I , Section I 

### 06 , d esc rib es the a utho1ity o f the FAA Ad mini s trator. Subti t l e VII, Av iation Programs , desc ri bes in more d e tail the scope of the Age nc y ' s a uthority . We are issuing this ru le makin g und er th e a uth o rity d escr ib ed in Su btitl e V II , Part A , S u bp a r t III , Sect ion 

### 4470 I , "Ge n e ral re quire m e nts." Under th at section, Congress 

### 1 5charges the FAA with promoti n g safe flight of c i vil a ir c r

aft in air commerce by pr

es crib in g re gu lations for practices , method s, and proced ures the Admini s trato r find s n ecessary for safe ty in a ir commerce. This reg ulation i s w i thin the sc ope of th at auth o rity because it addresses an unsafe cond iti o n th at i s likely t o ex i s t or develop on products id en tified in this rul emak in g action. Re g ulato ry Findings We h ave determined that thi s AD wi ll not have f e d e ralism implications und er Executive Order 13132. This AD w ill not have a substantial direct effect o n th e State s, on th e r e l

ationship between th e nati o n a l gove rnm ent and th e States , o r o n th e di strib u t io n of power and respo n s ibiliti es among th e va rio u s leve l s of gove rnm e nt. For th e reaso n s discussed above , I ce rtif y that this AD: ( 1) I s not a " s ign ifi can t regu latory action " und e r E xec uti ve Order 12866, (2) Is not a "s ig nificant rul e " under DOT R egu la to ry P o li c i es and P rocedures (44 foR 11034 , Feb r uary 26 , 197 9) , (3) Will not affect in trastate av iation in A la ska to the extent that it justifies making a regulatory distinction , and (4) Will not have a sig nifi cant econo mi c impact , positive or negat ive , on a s ub s tantial n umber of sma ll en titi es under th e cri teria of th e Regulatory F lex ibility Act. Li st of Subjects in 14 CF R Part 39 A ir transportation , Aircral1 , Aviation safety, In co rporati on by ref e re nc e, Safety. Adoption of th e Amendment Accord in g ly, under th e au th o rity d e le gate d to me by th e Admi ni s tr a tor , the FAA amends 14 

### CF R part 39 as follow s : 

### PART 39
- 

### AIRWORTHINESS DIRECTIVES 1

. The a u thori ty citation f or part 39 co ntinu es to read as follows: Auth o rity : 49 U

. S.C

. 10 6(g) , 401 1 3 , 44701. 16

### § 39.13 [Amended] 2. Th e FAA amends§ 39.13 by removi n g A irworthi n ess Dir ective (AD) 2012-09

- 09 , A m en dm ent 39 -170 44 (77 FR 30371, May 23 , 20 12) , a n d add in g the fo ll owi n g new AD: 

### 2014-36-01 International Aero E ngines AG: Amendm e nt 39- 1815 9 D ocket No
. 

## r: AA

- 2009- 11 00 ; Directorate Identifi e r 2009-NE

- 37 -AD. 

### (a) Ef fective Date

Thi s AD i s ef f ec tiv e [I NSERT DATE 35 DA Y S A I7TER DATE OF PUBLICAT I ON TN THE FE D E RAL RE G I S TER]. 

### (b) Affected ADs This A D rep laces AD 20 1 2-09-09 , Amendm e nt 39-17044 (77 FR 30371, May 23 , 2012). 

### (c) Applicability T hi s AD applies to: ( I ) A ll Int e rn atio nal Aero Engi n es AG (I A E) Y2500-A I turb ofa n eng in es; and (2) A ll IA E V2525-D5 and Y2528-D5 turbofan e n gi n es; and (3) TA E Y2522-A5, V2524- A5, V 2527-A5, Y2527E-A5 , V2527M -A 5 , V2530- A5 , a nd Y2533-A5 turbof a n engine s with se rial numb e r s (SINs) V 1000 I through Yl3 1 90 , a nd V 1 5001 through V16728 , exclud in g Yl6707. 

### (d) Unsafe Condition Thi s AD was prompted by the discovery th at addi ti onal attachment nuts for certain high-pres sure compr essor 

### ( HPC) stage 3 to 8 drum s cause the dru m to corrode and crack. We are issui n g th is AD to preve n t failure of th e HP C stage 3 to 8 drum , w hich
cou ld r es ult in uncontained drum fai lure, damage to the e n g in e, and damage to the
a irp l ane.

17

### (e) Co mpli a n ce Co mp ly with thi s AD within the comp l ianc e t ime s s p eci fied , unl ess a lready d o ne. You may use the in spec ti ons li sted in paragraph (h)(3) of thi s AD in stead of an ultr a s onic inspection (USI) for th e initial inspection required by para grap h s (e)(l) through (e)(5). If cracks are found durin g any of th e in s pection s required by this AD, remove the drum from se rvice before further fli g ht. 

### ( 1 ) Ini t i a l US I of t h e HPC stage 3 to 8 drum

- Gro up "A" a n d Gro up " B": For IAE V2500-A 1 turbofan eng in es with SINs li sted in "Gro up A " or " Group B " in paragraph I.E. in IAE A lert No n-M a ndator y Serv i ce Bull e tin (NMSB) No. V2500- ENG -7 2-A06 15 , R ev i sio n 6, dat ed Se pte mb e r 4 , 2 0 14, perform a n initial US Tof the HP C stage 3 to 8 drum wit hi n 200 cycle s of the drum accum u lating 8 , 000 cycl es o r w ith in 200 cycles from th e effective date of thi s A D , whichever occurs la t e r. 

### (2) Ini t i a l US l of t h e HPC stage 3 to 8 d rum - G r o u p "C": For IAE V2500-A5 turb ofan engines w ith SINs l isted in " Group C " in paragraph l.E . in IAE A lert NMSB No

. V 2500-ENG-72-A06 15 , Rev is ion 6, dat e d Sep tember 4, 2014 , perf orm a n i niti al UST of the HPC stage 3 to 8 drum withi n 200 cycles of the drum accumulating 6,250 cyc l es o r within 200 cycles from the effect ive date of this AD, wh ichever occu rs lat e r . 

### (3) In itia l USl of t h e HPC s t age 3 t o 8 d r u m - Gro u p " 0 " : For 

### IAE V 2500-A5 turbofan e ng in es with SINs li s ted in " Group D " in paragraph I. E. in IA E A lert NMSB No. V2500-ENG-72-A0615 , Revi s ion 6 , dated September 4 , 20 14 , perform an initi al USI of the HP C stage 3 to 8 drum wi thin 200 cyc les of the drum accumulating 3,750 cycles or within 200 cycl es fi ·o m th e e ff ec tive date of thi s AD , whiche v e r occurs lat e r.



### 18

### (4) Initial US I 

### of the HPC stage 3 to 8 drum

- Group "E": 

### Fo r I AE V2SOO-A I , -AS , 

### and

- D5 turb o f a n e ng in es n o t listed in " G r oup A , "

" Grou p B ," " Group C ," o r " Group D," and w ith dr um assemb l y part numb e rs (PINs) listed in

.. Group E" in paragraph l.E. in lAE 

### A l e rt NMSB No. V2SOO-ENG-72-A061S , Revi s ion 6 , dated Septe mber 4 , 20 14 , perform a n initi al US I of th e HP C stage 

### 3 to 

### 8 drum wi thin 200 cycle s of the drum accu mulating 1 2 , SOO cycle s o r w ithin 200 cycle s from th e effec tive date of this AD , which eve r occurs l ater. (5) Initial USI of the HPC stage 3 to 8 drum

- Group "F": 

### Fo r TAE V2SOO-A I , -AS , 

### and
- D S 

### turb o f an engine s no t lis t ed in " Group A ,"

" Group B ," " Group C ," or "G roup D, " and w i th drum assemb l y PIN s li s t ed in " Group r-'" 

### in paragr ap h I .E. in I AE Alert NM S B No

. V2SOO-ENG-72-A0615, Revi s ion 6 , d ated Sept embe r 4 , 20 14 , perform an initia l US I o f th e HP C sta ge 3 

### to 8 

### drum within 200 cycles of the drum accumulating 9 , 000 cycl es o r within 200 cyc l es fro m the effective date of thi s A D, whic heve r occurs la t er. (f) 

### Repetitive USis of t h e HPC Stage 3 to 8 Drum 

### ( I ) ror engine s in cluded in " Group A ," " Grou p B ," " Group C ," " GroupE ," or

· ' Group F ," as defined in paragraph (e) of this AD , perfom1 r e petitive US i s of the HP C stage 3 

### to 8 

### drum w ithin every ?SO 

### cycles of th e last US I after the initial in spec tion required b y paragraph (e) of thi s AD. 

### (2) For e ng in es in clu ded in " Gro up 0 , " as d efi ned in par ag raph (e) o f this AD , perform r epetitive US i s of the HPC s tage 3 

### to 8 

### dru m with in e ve r y SOO 

### cy c l es of the la s t US I afte r the initial in s pection required by para g r aph (e) of thi s AD. (3) 

### I f yo u in spec t the HP C s t age 3 

### to 8 

### drum at pi ece-pa rt expos ur e , you may de lay the nex t USI as s ho w n in th e " Grace Peri od s Table " for each compliance group listed in paragraph l.E. in IAE 

### Alert N MSB No. V2500-ENG-72-A061S , R ev ision 6 , dated S epte mbe r 4 , 20 1 4. 19(g) 

### US I Procedure for the In s p ecti on of the HP C Stage 3 to 8 Drum For the US I in s p ec tion s required by thi s AD , do the follow in g. In s p ect th e stage 8 di s k of the HP C s t age 3 to 8 drum o n the outer diam e t e r adjace n t t o the s tage 7 to 8
e lectro n beam w e ld la nd u s ing ultr asonic probe manipulator assembly 

### PIN IAE2R1986 5 for IAE Y2500-A I e n g in es, 

### P IN lAE2R 19852 or IAE 2R 19879 for IAE Y2500

- A5
e n gi nes, a nd 

### PIN IAE2 RI 9874 for IAE V2500- D 5 e n g i nes. In spec t the stage 8 disk ofthe HPC s tage 3 to 8 drum o n th e inn e r d i amete r at th e inn e r radiu s posit ion u s ing ultrason ic p robe man ipu lato r asse mbly 

### PIN IA E2 RI9870 for IAE V 25 00-A 1 e n gi nes, 

### P IN IAE2R 19859 o r IAE2R l 9 880 fo r IAE Y2500

-A5 e n gines, and 

### P IN IAE2R I 987 6 for IAE Y2500-D5 eng in es. In spec t th e full c ir c umf e ren ce of both the inn er and o ut e r diam e te rs. If th e e n tire circumf e r

e nce cannot b e in s pected , re m ove the drum from the e n g ine b efo re fu rther flight. ( I ) Calibrate th e ultra so ni c equ ipm e nt using the f ollow ing parameters an d th e accep tan ce criteri a li s ted in para g rap h 3.A.( l)(a) of IAE A le rt NMSB No. V 2 500-ENG

72-A0615, Revis io n 6 , dat e d September 4, 2014. Use wo rking standard 

### PIN 1A E2 Rl98 54 for o ut er d iameter inspec ti on and wo rkin g s tandard 

### P IN IAE2 R l 9860 for inner diameter in spec ti on: ( i) Set Fr e qu e ncy to 5 Mh z ( ii ) Set Rect i fy to Full Wave ( iii ) Set Pul se r t o S ingl e Crysta l ( iv) M ax imi ze the s ignal res p o n se to ac hi eve 70 percent fi. tll sc r ee n he ig ht (v) A dju st th e r a n ge control to position the target sig nal at 5.0 time base position based on ten div ision ti me base (v i) For o ut e r diameter in spec tion , se t Gate Po s it io n to 3.5

- 7.0 tim e base po si t ion based o n ten di visio n time bas e

20(vii) For inner diameter inspection, set Gat e Po s ition to 3.0

- 8.0 time base p osi ti o n based o n ten d iv i s ion time base (2) In spec t th e HPC stage 3 to 8 drum u s in g th e acceptance c rit e ri a li s ted in pa rag raph 3.A.( l )(a) of IAE Alert NMSB No. V2500- ENG-72-A0615 , Rev ision 6 , dated Sep t ember 4, 20 14 (3) Afte r co m pleti n g the inspect io n o f eac h f eat ure, ve rif y th e ca librat io n ofth e ultr aso nic equipme nt. 

### I f the calibra ti o n i s und e r sens iti v ity by more th a n 3 db , then re p eat th e ca libration and in spec tion of th e feature. (h) Removal of Si l ver-Plated Nuts At th e n ext pi ece- part expos ure of th e HP C s t age 3 to 8 drum after th e effec ti ve dat e of this AD, do th e following before re turning any HP C stage 3 to 8 drum to service: ( 1 ) Rem ove from serv ic e a ll si lver- pl ated nut s (fu ll y or p artiall y-p late d ), P INs AS44862 or AS64367 , th at attac h th e HPC s ta ge 3 to 8 drum to the HPC s tage 9 to 1 2 drum.

or (2) Clean th e HPC stage 3 to 8 drum to remove th e si lver re s idu e. 

### (3) Inspect the HPC stage 

### 3 to 8 drum using at least o n e of th e fo ll ow in g meth o d s: ( i) Fluore sce nt penetrant in spection (FPI) of th e HPC s ta ge 

### 3 to 8 drum for c ra cks ,
( i i) Eddy cu rrent inspection (EC I ) of the HP C stage 3 to 

### 8 drum for c racks

. (i) J nstallation Pro hibiti on After the effect ive date of thi s 

### AD, do not in sta ll a n y silver-p lated nuts , P IN AS44862 or AS64367 , into any e n g in e. 

## G) Mandatory Terminating Action Within 9,450 cyc le s after th e e ff ec tive date of thi s AD, but n o t la te r than D ece mb e r 31, 2025, in s tall:

2 1(1) 

### an HP C stage 3 to 8 drum th at has nev er o p erated with silver-plated nuts (fully
or partially p lated) to attach the HP C stage 3 

### to 8 

### drum to the HPC stage 9 to 12 drum , with (2) si lve r -f

r ee nuts to attach th e HPC sta ge 3 to 

### 8 drum t o the H 

### P C s tage 

### 9 to 12 drum. (k) D efi n i tion 

### For the puq)ose of this AD, " piece-part exposure" is removal of th e HPC stage 3 to 

### 8 drum from the en g in e, removal of a ll b lades from the drum, and separation of the HP C stage 3 

### to 8 

### drum from the stage 9 

### to 12 drum. (I) 

### Cre dit for Previous Actions 

### If you perfo rm ed an inspecti on of the HPC stage 3 to 8 drum before th e effective date of this AD using o n e of the following IAE NMSBs , you met the i nitial inspection requ irement of paragraph (e) of this AD: (i) IAE NMSB No. V2500-ENG-72-0608, R evis ion 3, dated September 20, 2011. (ii) IAE NMSB No. V2500-ENG-72-0615 , Revision 3, dated Septe mber 20 , 20 I l ; 

### IAE Ale rt NMSB No. V2500-ENG-72-0615 , R evision 4 , dated May 2 , 20 13; and IAE Alert NMSB No. V2500-ENG-72

- 0615, Revision 5, dated August 5, 20 14. (iii) IAE NMSB No. V2500-ENG-72-0638, dated Aprilll , 20 13. ( m) Alte rn ative Methods of Co mpli a nce (AMOCs) 

### The Manager, Engine Certification Office, FAA, may approve AMOCs for this AD. Use th e proc ed ure s found in 14 CF R 39 .1 9 to make your r equest. You may email your request to: ANE-AD-AMOC @ faa.gov. (n) R e lat ed Information ( I) 

### For more information about thi s AD, contact Martin Adler, Aerospace Engi nee r, Engine Cert ification Office , FAA, Engine & 

### Prope ll er Directorate, 12 New

22Eng land Executive Park , Burlin gton, MA 01803 ; phone: 78 1- 238-7 1 57 ; tax: 781-238- 7199 ; e mail: martin.adler @ faa.gov. (2) I AE NMS B No. V2500-ENG-72-0638 , da t e d Ap r il I I , 20 1 3 ; IAE NMS B No. V2500- ENG

- 72 -06 37 , dated May 2 , 20 1 3 ; IAE NMSB No. V2500-ENG-72-0625 , dated October 8 , 20 1 4 ; IA E EM Task 72-41-11-200-00 I ; a nd IA E E M T ask 72-41-11-110-001 , which are not incorporat e d by re ferenc e in thi s AD, ca n be ob ta in e d from IA E, usin g the
co nt act information in paragraph (o)(3) of thi s AD. IA E NMSB No. V2500 -EN G-72- 0638 , d ate d Ap ril I I , 2013 provide s guidance on p e rf o rmin g th e US l. IAE NMSB No. V2500-ENG-72-0637 and TA E E M T as k 72-41-1 I -200-00 I provide g uidance on perform ing th e FPI. Guidance on perform in g the ECI ca n b e fo und in IA E NMSB No. V2500

- ENG

- 72-0625. IAE Engine Manua l Task 72-4 I- I I- I I 0

- 00 I provides g uid ance on cl e ani n g the HPC stage 3 to 8 drum

. 

### (o) Material Incorporated 

### by Reference ( I ) T h e Dir ector of th e Fe de ra l Registe r app roved th e incorporation b y reference (IB R) of th e service in fo rmation listed in th i s paragraph und er 5 U.S.C. 552(a) and 1 CF R part 5 I. (2) You mu st u se this service inf ormat i o n as app li ca bl e to do the action s required by thi s A D , unle ss the A D spec i fies otherwise. ( i) Inte rnational Aero Eng ine s A l er t Non-Modification Se rvice Bulletin No
. Y2500-ENG

- 72-A06 15 , Rev i s ion 6, dated Sep tembe r 4 , 20 I 4

. (ii) Reserved. (3) For IAE se r vice information identified in thi s A D , con ta c t Int ernati onal Ae ro Engin es AG , 400 Mai n Street, East H a rtford , CT 06 11 8 ; phon e : 860-368-3700 ; fax: 860- 3 6 8-4600 ; e mail: iae inf o @ iaev2500.com ; Int ernet: htt ps ://www.iaewo rl d.com.

23(4) Yo u m ay v iew this service inform atio n at the FAA , E n gi ne & Propeller Directorate, 12 New E ng la nd Execut ive Park , Burlington, MA

. For inform at ion on th e ava il ab ility ofthi s material at the FAA , ca ll781 -238-7 1 25. (5) You m ay view this service information a t the Nationa l Ar c hi ves and Record s Adm ini s tra tion (NARA). For in fo rmation on 

### th e avai labil ity of this mate rial at NARA , call202-74 1 -6030 , o r go to: http: //www.arc hi ve s .gov / federal-register / cfr / ibrlocation s. html.

I ssued in Burli ngton , Massachusetts , on A pril 30 , 2015.

Co ll een M. D'A lessandro , Assistant Dir ectorat e Manager, E ng in e & Prop e ll e r Directora t e , A ir craft Ce rtification Se r v ice.

24