80 FR 59081 - Airworthiness Directives; Engine Alliance Turbofan Engines

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 80, Issue 190 (October 1, 2015)

We propose to adopt a new airworthiness directive (AD) for certain Engine Alliance (EA) GP7270 turbofan engines. This proposed AD was prompted by the manufacturer informing us that the inspection and repair criteria in the maintenance manual for aft bolt holes of the high-pressure compressor (HPC) cone shaft on the affected engines is incorrect. This proposed AD would require inspection of the HPC cone shaft and repair of affected parts, if needed. We are proposing this AD to prevent failure of the HPC cone shaft, which could lead to uncontained engine failure and damage to the airplane.

[Federal Register Volume 80, Number 190 (Thursday, October 1, 2015)]
[Proposed Rules]
[Pages 59081-59083]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2015-24731]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-3585; Directorate Identifier 2015-NE-22-AD]
RIN 2120-AA64


Airworthiness Directives; Engine Alliance Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness directive (AD) for 
certain Engine Alliance (EA) GP7270 turbofan engines. This proposed AD 
was prompted by the manufacturer informing us that the inspection and 
repair criteria in the maintenance manual for aft bolt holes of the 
high-pressure compressor (HPC) cone shaft on the affected engines is 
incorrect. This proposed AD would require inspection of the HPC cone 
shaft and repair of affected parts, if needed. We are proposing this AD 
to prevent failure of the HPC cone shaft, which could lead to 
uncontained engine failure and damage to the airplane.

DATES: We must receive comments on this proposed AD by November 30, 
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 
Engine Alliance, 400 Main St., East Hartford, CT 06108, M/S 169-10, 
phone: 800-

[[Page 59082]]

565-0140; email: [email protected]; Web site: 
sp.engineallianceportal.com. 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.

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-
3585; 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: Martin Adler, Aerospace Engineer, 
Engine & Propeller Directorate, FAA, 12 New England Executive Park, 
Burlington, MA 01803; phone: 781-238-7157; fax: 781-238-7199; email: 
[email protected].

SUPPLEMENTARY INFORMATION: 

Comments Invited

    We invite you to send any written relevant data, views, or 
arguments about this proposal. Send your comments to an address listed 
under the ADDRESSES section. Include ``Docket No. FAA-2015-3585; 
Directorate Identifier 2015-NE-22-AD'' at the beginning of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of this proposed AD. We 
will consider all comments received by the closing date and may amend 
this proposed AD 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 proposed AD.

Discussion

    We learned from the manufacturer that the inspection criteria and 
the repair procedures for the aft bolt holes of the HPC cone shaft, 
also referred to as the ``HPC forward stub shaft,'' were listed 
incorrectly in the maintenance manual for the Engine Alliance GP7270 
turbofan engines. HPC cone shafts inspected or repaired using the 
incorrect criteria in the maintenance manual could result in premature 
cracking of these parts. This condition, if not corrected, could result 
in failure of the HPC cone shaft, which could lead to uncontained 
engine failure and damage to the airplane.

Relevant Service Information Under 1 CFR Part 51

    Engine Alliance has issued EA Service Bulletin (SB) No. EAGP7-72-
329, dated July 21, 2015; and EA SB No. EAGP7-72-330, dated July 21, 
2015. The SBs describe procedures for shotpeening and inspection of the 
HPC cone shaft. This service information is reasonably available 
because the interested parties have access to it through their normal 
course of business or by the means identified in the ADDRESSES section 
of this NPRM.

FAA's Determination

    We are proposing this AD 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 proposed AD would require inspection of the HPC cone shaft and 
repair of affected parts, if needed.

Costs of Compliance

    We estimate that this proposed AD affects zero engines installed on 
airplanes of U.S. registry. The average labor rate is $85 per hour. 
Based on these figures, we estimate the cost of this proposed AD on 
U.S. operators to be $0.

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 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):

Engine Alliance: Docket No. FAA-2015-3585; Directorate Identifier 
2015-NE-22-AD.

(a) Comments Due Date

    We must receive comments by November 30, 2015.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Engine Alliance (EA) GP7270 turbofan engines 
with a high-pressure compressor (HPC) cone shaft, part number (P/N) 
382-100-907-0, installed.

(d) Unsafe Condition

    This AD was prompted by the manufacturer informing us that the 
inspection and repair criteria in the

[[Page 59083]]

maintenance manual for aft bolt holes of the HPC cone shaft on the 
affected engines is incorrect. We are issuing this AD to prevent 
failure of the HPC cone shaft, which could lead to uncontained 
engine failure and damage to the airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) For HPC cone shafts with serial numbers listed in EA Service 
Bulletin (SB) No. EAGP7-72-330, dated July 21, 2015, inspect the 
inner diameter of the HPC cone shaft aft bolt holes for nicks, 
dents, and scratches before accumulating 9,000 cycles since new 
(CSN). Do not reinstall the HPC cone shaft if the aft bolt hole has 
a nick, dent, or scratch that is greater than 0.002 inches in depth.
    (2) For HPC cone shafts with serial numbers listed in EA SB No. 
EAGP7-72-329, dated July 21, 2015, shot peen the HPC cone shaft aft 
bolt holes before accumulating 9,000 CSN. Use paragraph 1 of the 
Accomplishment Instructions in EA SB No. EAGP7-72-329 to do the 
shotpeening.

(f) Installation Prohibition

    After the effective date of this AD, do not install an HPC cone 
shaft onto an engine with the following:
    (1) A nick, dent, or scratch in an HPC cone shaft aft bolt hole 
that is greater than 0.002 inches in depth; or
    (2) any repair of an HPC cone shaft aft bolt hole that did not 
include shot peening.

(g) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, may approve AMOCs for 
this AD. Use the procedures found in 14 CFR 39.19 to make your 
request. You may email your request to: [email protected].

(h) Related Information

    (1) For more information about this AD, contact Martin Adler, 
Aerospace Engineer, Engine & Propeller Directorate, FAA, 12 New 
England Executive Park, Burlington, MA 01803; phone: 781-238-7157; 
fax: 781-238-7199; email: [email protected].
    (2) EA SB No. EAGP7-72-329, dated July 21, 2015; and EA SB No. 
EAGP7-72-330, dated July 21, 2015, can be obtained from EA using the 
contact information in paragraph (h)(3) of this proposed AD.
    (3) For service information identified in this AD, contact 
Engine Alliance, 400 Main St., East Hartford, CT 06108, M/S 169-10; 
phone: 800-565-0140; email: [email protected]; Web site: 
sp.engineallianceportal.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 September 24, 2015.
Colleen M. D'Alessandro,
Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-24731 Filed 9-30-15; 8:45 am]
BILLING CODE 4910-13-P