### DEPARTMENT O F TRANSPORTATION Federal Aviation Administration 14 CFR P a rt 39 [Docket N o. F AA - 2015-0277; Directorate Identifi e r 2015-N E -05-AD] RIN 2120-AA 6 4 Airworthine s s Directive s ; CFM Intern a tional 

### S.A. Turbofan E ngines AGENCY : Fede ral Avia ti o n Ad mini s trat ion (FAA), DOT. ACTION: Notice of proposed ru lemaking (N P RM). [4910-13 - P]

S UMMARY: We pro p ose to adopt a new a irworth iness d irec t ive (A D) for ce rta in CFM In te rn ationa l S.A. (CFM) CFM56

- 7B series t urb ofan engines. T his pro p osed AD was p ro mp ted by repo rt s of un co mm a nd ed in- f li g ht s hutd o wn s (IFSDs) o n CF M CF M 56

- 7B
e ng ines fo ll owing rup tu re of t h e 7 3- tooth gearshaf t lo cat e d in t h e eng in e access or y gea rbox (AGB). T hi s propose d AD wou ld req u ire magnetic chip detecto r ( M CD) in spec tio n of the affected gears h afts un ti l re mova l. We are propo s ing this A D to preven t fai lur e of certai n eng i ne AGB gears h afts , w h ich could l ead t o fai l ure of o ne or more e ng in es, l oss of thru st co ntro l, an d d a m age to th e a ir p l

a n e. DATES : W e mu st r ece ive c omm e nts o n thi s pro p ose d AD by [ I NSE RT DA TE 6 0 D AYS AFT E R D A T E O F PUBLI CAT ION TN THE F e dera l Register]. ADDRE S S ES : Yo u may se nd comme nt s , usi ng the pr oce d ures found i n 14 CFR 1 1 .43
a n d 11.45 , by a n y of the follow ing methods:
• Fe d era l e Rul e m ak in g Po rt a l : Go to http://www.regu latio n s . gov. Fo ll ow th e in s tru c ti o n s fo r s ub mittin g co mm e nt s . • Fax: 202-493-2251.
• Mail: U.S. Depart ment o f Transporta ti o n , D ocke t O p eratio n s, M -30 , West Building Gro un d Floo r, R oom W12-140 , 1200 New Jersey Ave n ue SE., Washi ng t on, DC 20590.• H an d De li ve r y : Del iver t o Ma il add ress a b ove betwee n 9 a.m. a n d 5 p . m ., Mo n day through Friday, except Federa l hol id ays. Fo r serv ice informat i o n identified i n t hi s AD , co n tact CFM In ternational I nc., Avia ti o n Op e rat io n s Ce n te r , l Neu m a nn Way, 

### MI D Room 2 8 5, C i n c inn at i , OH 4 5 1 25; p h one: 877

- 432-3272; fax: 877

- 432-3329; ema il : av iat io n .tleets u pport @ ge.com . Yo u m ay v iew till s serv ice informa tio n a t th e FAA, E n gine 

### & Propeller Directorate, 12 New E n g la n d Exec uti ve Pa rk , Burlin g ton, M A. Fo r i nformat io n o n th e ava il abi lit y o f t hi s m ater ia l a t th e FAA, ca ll 78 1

- 23 8-7 1 25. 

### E xa m ini ng th e A D Docket Yo u may exa min e th e AD docket on the In te rn e t at http: //www. r eg u lat io n s.gov by
sea rc hin g f or a n d loca tin g D oc ke t No. FAA-20 1 5

- 0277; o r in p e r so n at th e D ocke t Management Fac ili ty be t wee n 9 a.m. and 5 p. m. , Monday thro u gh Frid ay , excep t Federa l h o li days. The AD docket contains this proposed AD , the rebru lato ry eva l ua t ion, any co mm e n ts rece i ve d , a nd o th e r in fo r ma ti o n . Th e s tr eet a d d ress f o r th e Doc ke t Offi ce (p h o n e : 800-647-5527) is in t h e A DD RESSES sect io n . Com m ents wi ll be avai lab le in the AD docket s h o rt ly after rece ipt. 

### FOR FURT HER I NFORMAT ION CONTACT: Ky le Gus tafso n , Ae rospace E n g in eer , Engi n e Ce rtifi catio n Office, FAA, En g ine & P rope ll er D ir ectora te, 1 2 New En g land Executive P ark, B u rlington, MA 01803; phone: 78 1 -238-7 1 83; fax: 78 1 -238-7 1 99; email: kyle.gu stafson @ faa.gov. 

### SUPPLEMENTA RY INFORMAT ION : Co mments Inv i ted We inv ite you to send a n y wr itte n relevan t data , v iews, or arg u me n ts abou t t h is p roposa l. Se nd yo ur co mm e nts t o a n ad dress li s te d un de r th e A DD RESSES sec tion
. I nclude " D ocke t No. FAA

- 20 1 5

- 0277; D irec t o ra te Ide n tifier 20 1 5

- NE-05-AD" at t h e beginn in g o f your comments. We s p eci fi cally invite co m ments on the overall regu lato ry , 2eco nomic, env ironmenta l , an d e n ergy aspects of thi s proposed AD. We wi ll consider a ll
com m e n ts rec eived by the closing date and may amend th is proposed AD because of those comments. We w ill po s t a ll co mm e nt s w e rece ive, without c h a n ge, to http://www.regulations.gov, incl uding a n y personal inf o rmation yo u pr ov ide. We will
a l so post a report s umm ar izin g eac h s u bstantive verba l contact we receive abo u t this p ro p osed AD. 

### Discussion We h ave received reports ofuncomman d e d I FSDs on CFM CFM56-7 B engines follow in g rupture of th e 73-toot h gea rs haft located in the e ngi ne AGB. CF M h as id e ntif-i e d an aff ec te d popu lation of 73-too th gear s h afts that s how premature wear on th e teeth due to inad equa t e s h o t peening. In th e proc ess of its investigation , C FM id e nt i fied
a n addi t ional population of 41-to o th gears h afts that i s sub ject to the sa me premature wea r. T h e affected popu lation of 73- t ooth a nd 41-toot h geat·s haft s ex hibit a s urfac e fini s h th at leads to loss in o il film effect ive n ess, causing micro-pitting whic h eve ntually leads to ma terial se para tin g f rom the gearshaft and its eventua l failure. The propo se d AD require s e nh a n ced MCD in s pection unti l r e moval of the gear s h aft
. Th i s e nh a nc e d in spection r eq uires th at any m ate rial , includi ng fuzz, be sent to the particles lab for a nal ysis t o dete rm ine the source of the material. We are allowing affected engines to co ntinue to operate for 75 flight hou r s (FHs) after the MCD in spectio n to provide s u ffic ient tim e to d e t e rmine the so urce of th e m a t e ri a l and to remove the affected gears h aft if th e particl es lab ana lys i s finds that the sou rce of the material i s from an affecte d 73-tooth or 41-tooth gears h aft. The e nh a n ced MCD in spec tion and parti c les la b a n a lysis i s r e p ea t e d eve ry 500 FHs afte r the initi a l MCD in spec tion until th e affected gearshaft i s removed f rom service. Thi s co nditi o n , if not



### 3co rr ecte d , cou l d resu l t i n fa ilur e of ce rtai n eng i ne AG B gearshafts , wh ic h co ul d lead to f a ilur e of o n e o r mo r e e n g ine s, l oss of thru s t co ntrol , a nd d a m age t o th e a irpl a n e . 

### Relevant Service Information We reviewed CFM Se rv i ce Bu lletin (SBs) CFM56

- 7B 

### SIB 72-0964, Revis io n I , da t ed December 15 , 2014, and CFM56-7B 

### SIB 72

- 0965, d ated December 16 , 20 14. T he S B s describe p r ocedures for re m ova l of a f fected 73

- too th an d 41

- too th gea r s h afts. This
se rv ice in fo rm at io n i s reaso n a bl y ava il ab le; see A DDRE SSES f o r ways t o a c cess thi s se r v ice in fo rm atio n . 

### FAA ' s Determination We are proposi n g t his A D because we evalua t ed a ll the re leva nt info r mat io n an d de te rmi n ed th e u n sa f e cond iti o n desc ri bed prev io u s ly i s lik e ly to ex i s t o r deve lo p in o ther p ro du c t s o f th e sa me ty p e d es i g n. 

### Propo s ed AD Requirements T h is p roposed A D wou ld requi re an MC D in spection w it hin 250 FH s s i nce last ins p ection or w it h in 25 F H s afte r the effec ti ve da t e of th is A D , whichever comes later. The proposed AD wo ul d also requi re tha t th e MCD inspect io n be re p eate d eve ry 500 FHs afte r th e initi a l MCD in s p ec t ion until r e m ova l of th e affec t e d gear s h aft. Th e p ro p osed A D
wo ul d a l so re quire as te rminatin g ac ti o n th at th e affecte d gear s h afts be re m ove d. 

### Differences Betwe e n this Proposed AD and the Service Information T h is proposed A D wou ld req ui r e a n MCD i nspec tion 250 F H s si n ce last in spectio n or wi thi n 25 FHs after th e effec ti ve da t e o f thi s AD , w h ic h ever comes la t e r. CF M SB CFM56-7B 

### SI B 7 2 -0 964, R ev i s io n I , da t e d D ece mb er 1 5 , 20 1 4 , r eco mm e nd s p e r fo rmin g a M CD in s p ec ti o n 25 0 F H s s in ce last in s p ec ti o n o r as soo n as p oss ibl e i f th e inspect io n was done more th an 250 FH s ago. In this p roposed AD , we a r e not requi r in g that o p erators se n d the particl es to CFM for a n a lysis. We are, however, r eq u iring th at operato r s determi n e if the part icles are 473-tooth gears h aft o r 41-tooth gears h a ft material. CFM56-7 B S /B 72-0964 recomm e nd s that i f a n y m agnet ic p articles , inclu di n g fuzz are seen, operators se nd the inspection results and lab a n a lysis to CFM fo r dis p os iti on . 

### Cos t s of Compliance We est im ate th a t this proposed A D wo uld affect abo ut 67 e n gines in s ta ll ed on ai r pla n es ofU.S. registry. We also es tim ate that it wou ld take about 1 h o ur pe r eng i ne t o d o th e inspection a n d 8 hour s per e n g in e to rep lac e eac h affec ted gearshaft. We est im ate thirty-s ix 73-tooth gear s hafts and forty 4 1-to oth gears h a ft s w ill need r ep lace m e nt at a cos t of $12,480 and $7 , 680 p er part, respect ive l y. The ave rage labor ra t e is $85 p er h o ur. Based on these fi g ures, we estimate th e cos t of the proposed AD on U.S. ope rators t o be $8 1 3 , 855. Authority for thi s Rul e making Titl e 49 of the Un it ed States Co d e s p eci fi es th e FAA's aut h o r ity t o i ss ue rul es o n av ia ti o n safety. S u btitle I , section 1 06 , d esc rib es th e a uth o ri ty ofth e FAA Adm ini s tra tor. S u b titl e VII: Avia t ion Pro g ram s , d esc rib es in more detail th e scope of th e Age nc y's authority. We are i ss uin g thi s rulemakin g under the a u thor it y described in S ubtitle 

### Vll , P a rt A , S ubp art III , Sec tion 4470 I : "Ge n e ra l requireme nt s." Under th a t sect ion , Cong r ess charges th e F AA wi th p romoting safe fli g ht of civ il a i rcraft in air comme rce by prescribing regulat io n s for practices , methods, and procedures the Ad mini s trato r find s n ecess ary for sa f e ty in ai r commerce. Thi s reg ulati o n i s within the sco p e of that auth o rity becau se it addresses an unsafe condition that i s li kely to ex i s t or develop on products id e n tifi ed in thi s ru le makin g action. Re g ulatory Findings We d e te rmin ed that this proposed AD would n ot h ave feder a li s m impli cations under Executive O rde r 13132. This proposed AD would n ot h ave a substantial direct 5effec t on the S ta t es, o n the relation s hip between th e national Government and the States,
or on the di s tribution of power and r es p o n s ibi I i ties among the various levels of government. F or th e reaso n s discussed above, I ce rtif y thi s propo sed regulation: 

### (1) Is not a " s ign ifi cant regulatory ac ti o n " under Executive Order 1 2866, (2) Is n o t a " signi ficant rule " under th e DOT Reg ula tory Policies a nd Procedur es (44 

### FR 11034 , Fe bruary 26, 197 9), 

### (3) Will not affect intrastat e aviation in A laska to the ex t e nt that it justifi es makin g a regulatory di sti nction , and (4) Will n ot h ave a signifi cant eco n omic impact , p ositive or negat ive, o n a
s ubstan t ial numb er of s mall entiti es und e r the c rite ria of th e R eg ul ato ry Fl ex ibilit y Act. 

### List of Subjects in 14 CFR Part 39 Air tr a n spo rt a tion , Aircraft , Aviation sa fety , Incorporation by r efe rence , Safety. 

### The Propo sed Amendment Accord in g ly , under the authorit y del ega ted to m e b y th e A dmini s trator , the FAA proposes to amend 14 CFR part 39 as fo ll ows: 

### PART 39 -AIRWORTHINESS DIRE CT IVES 1. Th e a uthority citation for part 39 co ntinu es to r ead as follows: A uth o rit y: 49 U.S.C. 1 06(g) , 40113 , 4470 1. 

### § 39.13 [Am e nded] 2. Th e FAA a mend s§ 39.13 by a ddin g the following n ew a ir wo rthin ess directive (AD): 

### CFM International S.A.: Docke t No. 

### F AA -20 1 5- 0277 ; Dir ec t o r a t

e lcl e nti fier 20 15-N E05-AD.



### 6

### (a) Comments Due Dat e We must receive comments by [TNSERT DATE 60 DAYS AFTER DATE OF PUBLICATION 

### JN THE Federa l Register]. 

### (b) Affected A D s None. 

### ( c) Applicability This AD appl ies to CFM International S.A
. (CFM) CFM56-7B engi nes with accessory gea rbox es (AGBs), with 7 3-too th gea rshafts or 41-tooth gearshafts, identi fied in Appendix A a nd Appendix B of CFM Service Bulletin (SB) CFM56-7B S/ B 72-0964 , Re v ision 1, dated December 1 5,2014. 

### (d) U nsa fe Co ndition This AD was prompted by reports of uncommanded in-fli ght sh utdo wns on CFM CFM56-7B e n g ines following ruptur e of th e 73-tooth gearshaft loc ated in the engine AGB. We are issuing this A D to prevent failure of certain AGB gearshafts , which could lead to failure of one or more e n gines, lo ss of thrust contro l , a nd damage to the a i rp lane. 

### (e) 

### Compliance Comply with this AD with i n the complia n ce times specified , unless already don e . 

### (1) Initial Magnetic Chip Detector (MCD) In s pection and Analysis (i) For affec ted 73-tooth gearshafts, perform an MCD in s pection withi n 250 flight hours (F H s) s in ce la s t i nspection , w i thin 25 FHs from th e e ffecti ve date of th i s AD , or when the gears h aft accum ul ates 3 , 000 F H s si nce new, wh ichever comes later. (ii) Fo r affected 41-tooth gearshafts , perform an MCD in s pection w ithin 250 FHs si n ce last in spec tion , wit hi n 25 F H s fi·om the effective date of this A D , or when the geru·s haft accumu lat es 6 , 000 FH s since new , whichever comes later. (iii) If a n y magnet ic particl es, including fuzz , are seen , determ i ne w ith particle s lab anal ys i s i f th e particles are 73-too th or 41-tooth gearshaft mat e rial. 

### 7(i ii ) If any ma g netic p articles , including fuzz, are see n , det er min e with particle s lab ana l ysis 

### if the part icl es are 73-tooth or 41-tooth gearshaft materia l. (iv) If the particles are 73-tooth or 41

- tooth gem·shaft material , remo ve the affected gea r shaft(s) w ithin 75 FH s s in ce the MCD inspec ti on. 

### ( 2 ) R e petitive MCD In s pection and Ana lysis (i) For affec t ed 73-toot h gears h a ft s, perfom1 a n MCD inspection and particl es lab
ana lysis within every 500 FHs since the last MCD in spec tion until affected gearshaft i s removed. (ii) For affected 41-tooth gear s h afts , perform an 

### MCD inspect ion and particl es lab
a nal ysis within every 500 FHs since the last 

### MCD in spection unti l affected gearshaft i s re moved. (iii) If any magnetic particles , including fuzz , are see n , determ ine wit h part icles lab analysis if the particles are 73-tooth o r 41-tooth gears h aft materia l. (iv) If th e p a rticles are 73-tooth o r 41-tooth gea r s h aft material, r e move the affected gearshaft(s) within 75 FI-ls s in ce the 

### MCD in spect ion. (f) 

### Mandatory Te rmin a tin g Action (1) Remov e the affected 73-tooth gearshaft prior to the gearshaft accu mulatin g 6,000 FI-l s si nce new or within 50 FHs afte r th e effec tiv e date of thi s AD, whichever
comes later. (2) Remo ve the affected 41-tooth gears haft prior to the gearshaft accu mulatin g 9,000 FI-ls since new o r wit hin 50 fHs afte r the effecti ve date of this AD, wh ic hever comes later. 

### (g) In sta llation Pro hibition After the effective date of th is AD, do not in s tall an affected gear s h aft into an 

### AGB.

8

### (h) Alternative Methods of Compliance (AMOCs) T h e Mana ge r , E n gi n e Certification Office, FAA, m ay app r ove AMOCs for this AD. U se th e proc e du r es found in 14 CFR 39 .19 to make your re qu es t. You may emai l yo ur requ es t t o : ANE-AD-A MO C @ faa.gov. 

### (i) Relate d Information (I) For more information about thi s A D , contac t K y le Gustafson , Aeros p ace E ngin ee r , E n gine Ce rtification Offic e, FAA , E n gi ne & Prop e ll er Dir ec torate, 12 New Eng land Exec uti ve P a rk , Burlin gto n , MA 0 1 803 ; phone: 781- 238-7 18 3; fax: 781

- 23 8-7199 ; e mai 

### I : ky le . g u stafson @ f aa . gov. (2) CF M S B s CFM56 -7B 

### S I B 72-0964 , R evisio n 1, dated D ece mb e r 15 ,20 14 , and CFM56

- 7B SIB 72-0965, dated D ece mb e r 1 6 , 2014, w hi ch are n ot incorporated by
reference in thi s propo se d AD , can b e ob t a in e d from GE u s ing th e co ntact information in paragraph ( i )(3) of this proposed AD. (3) For se rvic e information id e ntifi e d in this AD , co ntac t CFM Jnt e rn at ionallnc
. , Av iat io n Ope rat io n s Ce nte r , 1 Ne uma nn Way , 

### MI D Room 285 , Ci n c inn a ti , O H 45125 ; phon e: 877-432-3272; fax: 877-4 32

- 3329 ; e mai l : aviat io n .fleetsupport @ ge .com . (4) Y o u m ay v iew th i s serv ice inf or ma tion a t th e FAA , E n g in e 

### & Propelle r Dir ectorate , 1 2 N e w E n g land Execu tiv e P a rk , Burlington , M A. Fo r info rm a ti on on the
ava i labil ity ofthi s m a t e ri a l at th e FAA, ca ll 78 1 -238 -7 1 25.
I ssu e d in Burli ngt o n , Ma ssachu se tt s , on Apri l 17 , 2 015.



# ~~ Acti n g M a n ager , En g in e & Prop e ll e r Di rec t o rat e , A ircraft Certi fica t ion Se rv ic e .


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