DEPARTMENT OF TRANSPORTATION 

Federal Aviation Administration 

14 CFR Part 39 

!Docket No. FAA-2015-2984; Directorate Identifier 2015-NE-21-ADI 

RIN 2120-AA64 

Airworthiness Directives; General Electric Company Turbofan Engines 

AGENCY: Federal Aviation Administration (FAA), DOT. 

ACTION: Notice of proposed rulemaking (NPRM). 

[4910-13-Pl 

SUMMARY: We propose to adopt a new airworthiness directive (AD) for all General 

Electric Company (GE) GEnx-1 854, -I 858, -I 864, -I 867, and -I 8 70 turbofan engine 

models. This proposed AD was prompted by reports of two in-flight shutdowns (IFSDs) 

caused by high-pressure turbine (HPT) rotor stage I blade failure. This proposed AD 

would require inspection and conditional removal of affected HPT rotor stage 1 blades. 

We are proposing this AD to prevent failure of the HPT rotor stage 1 blades, which could 

lead to failure of one or more engines, loss of thrust control, and damage to the airplane. 

OATES: We must receive comments on this proposed AD by [INSERT DATE 60 

DAYS AFTER DATE OF PUBUCATION IN THE Federal Register]. 

ADDRESSES: You may send comments, using the procedures found in 14 CFR 11.43 

and 11.45, by any of the following methods: 

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the 

instructions for submitting comments. 

• Fax: 202-493-2251. 

• Mail: U.S. Department ofTransportation, Docket Operations, M-30, West 

Building Ground Floor, Room Wl2-140, 1200 New Jersey Avenue SE., Washington, DC 

20590. 
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., 

Monday through Friday, except Federal holidays. 

For service information identified in this proposed AD, contact General Electric 

Company, GE Aviation, Room 285, I Neumann Way, Cincinnati, OH 45215; phone: 

5 13-552-3272; email: aviation.fleetsupport@ge.com. You may view this service 

information at the FAA, Engine & Propeller Directorate, 12 New England Executive 

Park, Burlington, MA 01803. For information on the availability ofthis material at the 

FAA, call 781-238-7 125. 

Examining the AD Docket 

You may examine the AD docket on the Internet at http://W\V\v.regulations.gov by 

searching for and locating Docket No. F AA-20 15-2984; or in person at the Docket 

Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal 

holidays. The AD docket contains this proposed AD, the regulatory evaluation, any 

comments received, and other infom1ation. The street address for the Docket Office 

(phone: 800-647-5527) is in the ADDRESSES section. Comments will be available in the 

AD docket shortly after receipt. 

FOR FURTHER INFORMATION CONTACT: Christopher McGuire, Aerospace 

Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, 12 New 

England Executive Park, Burlington, MA 01803; phone: 781-238-7120; fax: 781-238-

7 199; email: chris.mcguire@faa.gov. 

SUPPLEMENTARY INFORMATION: 

Comments Invited 

We invite you to send any written relevant data, views, or arguments about this 

NPRM. Send your comments to an address listed under the ADDRESSES section. 

Include "Docket No. F AA-20 15-2984; Directorate Identifier 20 15-NE-21-AD" at the 

beginning of your comments. We specifically invite comments on the overall regulatory, 

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economic, environmental, and energy aspects of this NPRM. We will consider all 

comments received by the closing date and may amend this NPRM 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 verbal contact we receive about this 

NPRM. 

Discussion 

We propose to adopt a new AD for all GE GEnx-1 B54, - I 858, -1864, -1867, and 

-I B70 turbofan engine models. This proposed AD was prompted by reports of two IFSDs 

caused by HPT rotor stage 1 blade failure. This proposed AD would require inspection 

and conditional removal of affected HPT rotor stage I blades. This condition, if not 

corrected, could result in failure of the HPT rotor stage I blades, which could lead to 

failure of one or more engines, loss of thrust control, and damage to the airplane. 

Related Service Information 

We reviewed GE GEnx- 1 B Service Bulletin (SB) No. 72-0267 ROO, dated April 

10,2015. The SB describes procedures for borescope inspection (BSI) ofthe HPT rotor 

stage I blades. 

FAA's Determination 

We are proposing this NPRM 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 same type design. 

Proposed AD Requirements 

This NPRM would require initial and repetitive BSI and conditional removal of 

a ffected HPT rotor stage I blades. 

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Costs of Compliance 

We estimate that this proposed AD will affect 4 engines installed on airplanes of 

U.S. registry. We also estimate that it will take about 2 hours per engine to comply with 

this proposed AD. The average labor rate is $85 per hour. Based on these figures, we 

estimate 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 authority to issue rules on 

aviation safety. Subtitle 1, section I 06, describes the authority of the FAA Administrator. 

Subtitle Yll: Aviation Programs, describes in more detail the scope ofthe Agency's 

authority. 

We are issuing this rulemaking under the authority described in Subtitle V II , 

Part A, Subpart III, Section 44 701: "General requirements." Under that section, Congress 

charges the FAA with promoting safe fl ight of civi l aircraft in air commerce by 

prescribing regulations for practices, methods, and procedures the Administrator finds 

necessary for safety in air commerce. This regulation is within the scope of that authority 

because it addresses an unsafe condition that is like ly to exist or develop on products 

identified in this rulemaking action. 

Regulatory Findings 

We determined that this proposed AD would not have federalism implications 

under Executive Order 13132. This proposed AD would not have a substantial direct 

effect on the States, on the relationship between the national Government and the States, 

or on the distribution of power and responsibi I ities among the various levels of 

government. 

For the reasons discussed above, I certify this proposed regulation: 

(I) Is not a "significant regulatory action" under Executive Order 12866, 

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(2) Is not a "significant rule" under the DOT Regulatory Policies and Procedures 

(44 FR II 034, February 26, 1979), 

(3) Will not affect intrastate aviation in Alaska to the extent that it justifies 

making a regulatory distinction, and 

(4) Will not have a significant economic impact, positive or negative, on a 

substantial number of small entities under the criteria of the Regulatory Flexibility Act. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. 

The Proposed Amendment 

Accordingly, under the authority delegated to me by the Administrator, the FAA 

proposes to amend 14 CFR part 39 as follows: 

PART 39- AIRWORTHINESS DIRECTIVES 

I. The authority citation for part 39 continues to read as follows: 

Authority: 49 U.S.C. 106(g), 401 13,44701. 

§ 39.13 !Amended) 

2. The FAA amends§ 39.1 3 by adding the following new airworthiness directive 

(AD): 

General Electric Company: Docket No. FAA-20 15-2984; Directorate Identifier 2015-

NE-2 1-AD. 

(a) Comments Due Date 

We must receive comments by [INSERT DATE 60 DAYS AFTER DATE OF 

PUBLICATION IN THE Federal Register]. 

(b) Affected ADs 

None. 

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(c) Applicability 

This AD applies to all General Electric Company (GE) GEnx- 1 854, -1858,-

I 8 64, -1867, and - I 870 turbofan engines with high-pressure turbine (HPT) rotor stage I 

blade, part number 2305M26P06, installed. 

(d) Unsafe Condition 

This AD was prompted by reports of two in-fl ight shutdowns caused by HPT 

rotor stage I blade failure. We are issuing this AD to prevent failure of the HPT rotor 

stage 1 blades, which could lead to failure of one or more engines, loss of thrust control, 

and damage to the airplane. 

(e) Compliance 

Comply with this AD within the compliance times specified, unless already done. 

( I) After the effective date ofthis AD, perform an initia l borescope inspection 

(BSI) of the convex surface of the HPT rotor stage I blades for axial cracks from the 

platform to 30% span, within I ,000 blade cycles since new or 25 cycles in service, 

whichever comes later, and disposition as follows: 

(i) If any axial crack with a length greater than or equal to 0.3 inch is found, or if 

any axial crack of any length turning in a radial direction is found, or if more than one 

axial crack of any length is found, remove the cracked blade before further fl ight. 

(ii) If an axial crack is found with a length greater than or equal to 0.2 inch and 

less than 0.3 inch, remove the cracked blade within I 0 blade cycles in service. 

(iii) If an axial crack is found with a length greater than or equal to 0.1 inch and 

less than 0.2 inch, inspect the cracked blade within 50 blade cycles since last inspection 

(CSLI). 

(iv) lf an axial crack is found with a length less than 0.1 inch, inspect the cracked 

blade within I 00 blade CSLI. 

(v) If no cracks were found, perform a 8 SI ofthe blades within 125 blade CSLI. 

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(2) Thereafter, perform a repetitive BSI of the convex surface ofthe HPT rotor 

stage 1 blades for axial cracks from the platform to 30% span within 125 blade CSLI and 

disposition as specified in (e)(1)(i) through (e)(l)(v), or remove the blades from service. 

(f) Definition 

For the purpose of this AD, a "blade cycle" is defined as the number of engine 

cycles that a set of rotor blades has accrued, regardless of the engine(s) in which they 

have operated. 

(g) Alternative Methods of Compliance (AMOCs) 

The Manager, Engine Certification Office, FAA, may approve AMOCs to 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 Jnformation 

(1) For more information about this AD, contact Christopher McGuire, Aerospace 

Engineer, Engine Certification Office, FAA, Engine & Propeller Directorate, I 2 New 

England Executive Park, Burlington, MA 01803; phone: 781-238-7 120; fax: 78 1-238-

7199; email: chris.mcguire@faa.gov. 

(2) GE GEnx-lB Service Bull etin No. 72-0267 ROO, dated April 10, 2015 can be 

obtained from GE using the contact information in paragraph (h)(3) of this proposed AD. 

(3) For service information identified in this proposed AD, contact General 

Electric Company, GE Aviation, Room 285, 1 Neumann Way, Cincinnati, OH 45215; 

phone: 513-552-3272; email: aviation.fleetsupport@ge.com. 

( 4) You may view this service information at the FAA, Engine & Propeller 

Directorate, 12 New England Executive Park, Burlington, MA. For information on the 

availability ofthis material at the FAA, call 781-238-7 125. 

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Issued in Burlington, Massachusetts, on August 21, 2015. 

Colleen M. D' Alessandro, 

Directorate Manager, Engine & Propeller Directorate, 

Aircraft Certification Service. 

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