```

[Federal Register Volume 80, Number 166 (Thursday, August 27, 2015)]
[Proposed Rules]
[Pages 51965-51966]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-21120]

=======================================================================
-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-2984; Directorate Identifier 2015-NE-21-AD]
RIN 2120-AA64

Airworthiness Directives; General Electric Company Turbofan 
Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: We propose to adopt a new airworthiness directive (AD) for all 
General Electric Company (GE) GEnx-1B54, -1B58, -1B64, -1B67, and -1B70 
turbofan engine models. This proposed AD was prompted by reports of two 
in-flight shutdowns (IFSDs) caused by high-pressure turbine (HPT) rotor 
stage 1 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.

DATES: We must receive comments on this proposed AD by October 26, 
2015.

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 of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 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, 1 Neumann Way, 
Cincinnati, OH 45215; phone: 513-552-3272; 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 of this 
material at the FAA, call 781-238-7125.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov by searching for and locating Docket No. FAA-2015-
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 information. 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: 781-238-7199; 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. FAA-2015-2984; 
Directorate Identifier 2015-NE-21-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
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-1B54, -1B58, -1B64, -
1B67, and -1B70 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 1 blades. This condition, if not corrected, 
could result in 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.

Related Service Information

    We reviewed GE GEnx-1B Service Bulletin (SB) No. 72-0267 R00, dated 
April 10, 2015. The SB describes procedures for borescope inspection 
(BSI) of the HPT rotor stage 1 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 affected HPT rotor stage 1 blades.

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 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII: Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701: ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil 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 likely to exist or develop on

[[Page 51966]]

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 responsibilities among the various levels of government.
    For the reasons discussed above, I certify this proposed 
regulation:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under the DOT Regulatory Policies 
and Procedures (44 FR 11034, 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

0
1. The authority citation for part 39 continues to read as follows:

    Authority:  49 U.S.C. 106(g), 40113, 44701.

Sec.  39.13  [Amended]

0
2. The FAA amends Sec.  39.13 by adding the following new airworthiness 
directive (AD):

General Electric Company: Docket No. FAA-2015-2984; Directorate 
Identifier 2015-NE-21-AD.

(a) Comments Due Date

    We must receive comments by October 26, 2015.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all General Electric Company (GE) GEnx-1B54, 
-1B58, -1B64, -1B67, and -1B70 turbofan engines with high-pressure 
turbine (HPT) rotor stage 1 blade, part number 2305M26P06, 
installed.

(d) Unsafe Condition

    This AD was prompted by reports of two in-flight shutdowns 
caused by HPT rotor stage 1 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.
    (1) After the effective date of this AD, perform an initial 
borescope inspection (BSI) of the convex surface of the HPT rotor 
stage 1 blades for axial cracks from the platform to 30% span, 
within 1,000 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 flight.
    (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 10 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) If an axial crack is found with a length less than 0.1 
inch, inspect the cracked blade within 100 blade CSLI.
    (v) If no cracks were found, perform a BSI of the blades within 
125 blade CSLI.
    (2) Thereafter, perform a repetitive BSI of the convex surface 
of the 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)(1)(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 Information

    (1) For more information about this AD, 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: 781-238-7199; email: 
chris.mcguire@faa.gov.
    (2) GE GEnx-1B Service Bulletin No. 72-0267 R00, 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 of this material at the FAA, 
call 781-238-7125.

    Issued in Burlington, Massachusetts, on August 21, 2015.
Colleen M. D'Alessandro,
Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-21120 Filed 8-26-15; 8:45 am]
 BILLING CODE 4910-13-P
```