### DEPARTM ENT OF TRANSPORTAT ION Feder al Av i ation A dm in istration 14 CF R Part 39 !D ocket No
. FAA-2 015-2984 ; Directorate Id entifier 2015 -N E

- 2 1- ADI RIN 2 1 20-AA64 Airworthiness Directives; General Electric Com p any Turbofa n Engines AGENCY : Federa l Aviation Administration (FAA), DOT. 

### ACT I ON: Notice of proposed rulemaking (NPRM). 

### [4910-13-Pl

SUMMARY: We propose to adopt a new airworthiness directive (AD) fo r all General Electric Co mpany (GE) GEnx-1 854, -I 858, -I 864, -I 86 7, a nd -I 8 70 turbofan engine mode ls. Thi s proposed AD was prompted by reports of two in-flight sh utdo wns ( IFSD s)
cause d by high-p ressure turbine (HP T ) rotor stage I b lade failure. This proposed A D
wou ld req uire in spection and conditional remova l of affecte d HPT rotor stage 1 b lades. We are propo si ng th is AD to prevent failure of th e HPT r o tor stage 1 blades, which cou ld l ead to failure of one or more engines, lo ss of thrust contro l, and damage to the airplane. 

### OATES: We must receive comments on thi s propo se d AD by [ I NSERT DATE 60 DAYS AFTER DATE OF PUBU CATION IN THE Federa l Register]
. 

### ADDRESSES: You may send comments, u s ing the proc e dure s found in 14 CFR 11.43 and 11.45 , by any of the following method s:
• Federal eRulemaking Po rtal: Go to http: //www.regulations.gov. Follow the instructions for s ubmitting comments.
• Fax: 202-493-2251.
• Mail: U.S. Departm e nt ofTransportation , D ocke t Operations, M-30, West Buildin g Ground F loor, Room Wl2-140 , 1200 New Jersey Avenue SE., Washington , D C 20590.

### • Hand Delivery: Deliver to Ma il address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. For serv ic e information identifi e d in this proposed AD, contac t Gene ral El ect ric Compan y, GE Aviation, Room 285, I Neumann Way , Cinc inn ati , OH 45215; phone: 5 1 3-552-3272; email: aviation.fleetsupport @g e.com. You may v i ew this service inform at ion at the FAA, Engine & 

### Propell er Directorate, 12 New E ngland Executive Park , Burlington, MA 01803. For information on the avai lability ofthis mate rial at the FAA, call 781-238-7 12 5
. Examining the AD Docket 

### You may examine the AD docket on the Internet at http: //W\V\v.regulations.gov by
searc hin g f or and locatin g Docket No. F AA-20 15-2984; or in person at th e Docket Managemen t Facility between 9 a.m. and 5 p.m. , Monday through Friday, except Federal holidays
. The AD docket contains this proposed AD, the regulatory eva l uation, any
com m ents received , and other infom1ation. The street a ddress for the Docket Office (phone: 800-647-5527) is in the ADDRESSES sectio n . Commen t s will be available in the AD docket s hortly after receipt. FOR FURTHER INFORMATION CONTACT: 

### C hri s topher McGuire , Aerospace E ng ine e r, Engine Certification Office , FAA, Engine & 

### Prope ll er Directorate, 12 New Eng land Exec utive Park , Burlington , MA 01803; phone: 781-238-7120; fax: 781-238- 7 199 ; e mail: chris.mcguire @ faa.gov. SUPP L EMENTARY INFORMATION: Com m en ts Invited 

### We in vite you to send any written relevant data , views, or arguments about this NPRM. Send your comments to an address li sted und e r the ADDRESSES section
. Include " D ocket No. F AA-20 15-2984; D i rectorate Id entifie r 20 15-NE-21-AD" at the beginning of your comments. We speci fically invite com m e nt s on the overall regulatory , 

### 2eco n omic, environ mental , and energy aspects o f thi s NPRM. We will co n sider all
co mm ents rece ived by the closing date and may ame nd thi s N PR M because of those
com m e nts. We w ill post all comments we rece i ve, with out change, to http: //www.regulations.gov, includin g any personal info r mation you provid e. We will
a lso post a re port s ummarizing each substa ntiv e ve rb al co ntact we receiv e about this N PRM. Discussion We propose to adopt a n ew AD for a ll GE GEnx-1 B54,

- I 858,

- 1864 , -1867 , and -I B70 turbofan e n g ine model s. Thi s proposed AD was prompted by reports of two IF S D s caused by HPT rotor stage 1 blade failure. Thi s p roposed A D wou ld req uir e inspection
a nd co n di ti ona l remova l of affected HPT ro tor s tage I blades. This co ndi t ion, if n ot corrected, could resu lt in failu re of the HPT ro tor s tage I blades, whic h could lead to fail u re of o n e or more e n gi ne s, loss of th ru st co ntro l , and da ma ge to t he a ir plane. Related Service Information W e rev iewe d GE GEnx- 1 B Ser v i ce Bull e tin (SB) No. 72-0267 ROO , dated Ap ril 10,20 1 5. The SB describes procedur es for borescop e in spec ti o n (B S I ) ofth e HPT rotor
s t age I blad es. FAA ' s Determination We are proposi n g th i s NPRM because we evaluated a ll the re leva nt information and det e rmined the un safe condition described prev iously i s like ly to ex i st o r develop in
o th e r p roduc t s o f th e same ty p e design. Propo se d AD Requirement s T hi s N PRM wo uld require initial an d repetit ive BS I a nd co nd itional removal of
a ff ected HP T rotor stage I b lades.

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### Cos ts of Co mpliance We estimate that this prop osed AD will a f fect 4 engines installed on airplanes of U.S. registry. We a l so estimate that it w ill take about 2 hours per engine to comply w ith this p roposed AD. The average labor rate is $85 per hour. Based on these figures, we est imate the total cost of this proposed AD to U.S. operators to be $680. 

### Authority for this Rulemaking Title 49 ofthe United States Code specifies the FAA 's author ity to i ssue rules on aviation safety. Subtitl e 1 , section I 06 , de sc rib es the authority of the FAA Adm ini strator. Subtitle 

### Yll : Aviation Programs, describes in more detail the scope ofth e Agency's authority. We are issuing this rulemaking under the au thorit y described in Subtitle V II , P art A , Subpart III , Section 44 701: "Ge nera l requirements. " Under that sect ion , Co n gress charges the FAA with promoting safe fl ight of civi l aircraft in a ir commerce by prescribing regulations for practices, me th ods, and procedures the Administrator finds necessary for safety in air commerce. Thi s regulation i s within the scope of that authority because it add resses an unsafe condition that i s lik e ly to ex i s t or develop on products id ent ified in this rulemaking act i on. 

### Re g ulatory Findings W e d ete rmined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not ha ve a substantial direct effect o n th e States, on the relationship between the nati onal Government and the States,
or on the d i s tributi o n of power and responsibi I ities amo n g the various levels of government. For the reasons di scussed above , I cert i fy this proposed regu lation: (I) Is not a "significant re gu latory action " under Executive Order 12866,



### 4(2) Is not a "significant rule " und e r the DOT Regulatory Po licie s and Procedur es (44 FR II 034, February 26, 1979) , (3) Will n ot affect intra state aviation in Ala s ka to th e extent that it justifies making a reg ulatory distinction , and (4) Will not have a significant economic impact , positive or negative, on a
s ub s t a ntial number of small entities under th e cri teria of th e Reg ulatory F lexibility Ac t. 

### List of S ubjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safe ty , Incorporation by reference, Safety. 

### The Proposed Amendment Accordingly , under the authority de legated to me by the Adm inistrator, the FAA propo ses to amend 14 CFR part 39 as foll ows: 

### PART 

### 39- AIRWORTHINESS DIRE CT IV ES I. Th e authority citatio n for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 401 1 3,4470 1. 

### § 39.13 !Amended) 2. Th e FAA amends§ 39 .1 3 by adding the following new airworthiness directive (AD): 

### General Electric Company: Docket No. FAA-20 15-2984 ; D irectorate Id ent i fier 20 1 5- NE-2 1 -AD. 

### (a) Co mm e nts Due Date We must receive comments by [INSERT DATE 60 DAYS AFTER DATE OF P UB LI CAT ION I N THE Fed era l Regi s te r]
. 

### (b) A ff ected ADs None.



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### (c) Applicabili ty Thi s AD ap p l ies to a ll Ge n eral E lec tri c Co m pa ny (GE) GE n x- 1854, -185 8,- I 8 64,

- 1 867, and

- I 870 tu r bofa n eng in es w i th hi g h -p r ess u re turbi n e (H PT) roto r stage I b lade , part n umber 2305M26 P 06, in sta ll ed. 

### (d) Unsaf e C ondition T h is AD was pro m pted by reports of two i n - fl ight s h utdow n s caused by HPT
ro to r stage I b lade f ai lure. We are iss uin g th is A D to pr event fa i lure of th e HP T rotor
s t age 1 b lades, w hi c h co uld lead to fa ilure of o n e o r mo re e n g in es, loss of thru st co ntro l, a n d d amage to the airp la n e. 

### ( e ) Complianc e Comply with this A D w ithin th e compliance ti mes spec i fied, u nl ess al r eady do n e. 

### ( I ) After the effec ti ve d a te ofthi s AD, p e r fo rm a n i n it i a l borescope in s p ec ti o n ( B S I ) o f th e co n vex s ur fa c e o f th e HP T r oto r stage I b la d es for ax ia l c rac k s fro m the p latform to 30% span, w ithin I , 000 b lade cycles s in ce new or 25 cycles in service, whicheve r comes later, and disposition as follows: (i) If a ny ax ia l crack with a length greate r than or equal to 0.3 in ch is found, or if
a ny ax ial crack of a n y l e n gth tu rn i ng in a radial direc ti o n i s fo un d, o r i f m ore th a n o n e ax ia l c rac k of a ny le n g th i s f o und , re m ove the crac k e d bl a d e before fu rth e r fl ig ht. ( ii ) 

### I f a n axial crack is fou n d with a le n gth g reater th an or equal to 0.2 in c h and less tha n 0.3 i nc h , remove the cracked b la d e with in I 0 blade cycles in service. ( iii ) I f an ax ia l crack is found wi th a length greater than or equa l to 0.1 inch and less th a n 0
. 2 i nc h , in spect the cracked blade w ith in 50 b lade cyc l es s i nce last inspection (CS LI ). (iv) l f an ax ia l c rack is found w ith a le n gth less th an 0.1 inch, inspect the cracked b la d e w ithin I 00 blade CSLI. (v) If n o cracks were foun d , perform a 8 SI ofthe blades within 1 25 blade CSLI. 

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### (2) Thereafter, perform a repetitive BSI of the convex s urface ofthe HPT rotor stage 1 

### blades for axial cracks from the p latform to 30% span within 125 blade CSLI and disposition as specified in (e)(1)(i) throug h (e)(l)(v), or remov e the blades from serv ice. (f) Definition 

### For the purpose of this AD, a "blad e cyc l e" is defined as the number of engine cycles that a set of rotor blades has accrued, regard less of the engine(s) in wh ich they have ope rated
. (g) 

### Alternative Methods of Compliance (AMOCs) 

### The Manager, Engine Certification Offic e, FAA, may approve AMOCs to this AD. Us e the procedures found in 14 CFR 39.19 to make your reques t. You may ema il your request to: ANE-AD-AMOC @ faa.gov. (h) Related Jnformation 

### (1) For more information about this AD, contact Christopher McGuire, Aerospace Engineer, Engine Certification Office, FAA , Engine & 

### Prop e ll er Directorate, I 2 New England Executive Park, B urlin gton, MA 01803; phone: 781-238-7 120; fax: 78 1- 238

- 7199; email: chri s.mcg ui re @ faa.gov. (2) GE GEnx-lB Service Bu ll et in No. 72-0267 ROO , dated Apr il 10 , 2015 can be obta ined from GE using the contact inf ormation in paragraph (h)(3) of this proposed AD
. (3) For service in formation identified in thi s proposed AD , contact Ge nera l Electric Co mpany, GE Aviation, Room 285, 1 Neumann Way, Cincinnati, OH 45215; p hone: 513-552-3272; ema il: av iation .fl eets upport @ge.co m. ( 4) You may v iew this serv i ce information at the FAA, Eng ine & 

### Propeller Directorate , 12 New Eng land Execu ti ve Park , Burlington , MA. For info rm ation on the availability ofth i s materia l at the FAA, ca ll 781-238-7 125
.

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### Issued in Burlin gto n , Massachusetts , on August 2 1 , 2015.

Co lleen M. D ' Alessandro, Directorate Manage r, E ngine & Propelle r Directorate , Aircraft Cer tific atio n Serv ice.

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