[Federal Register Volume 80, Number 205 (Friday, October 23, 2015)]
[Proposed Rules]
[Pages 64373-64375]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-26755]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2015-3713; Directorate Identifier 2015-NE-23-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 reports of the installation of non-conforming honeycomb 
seals in the high-pressure compressor (HPC) adjacent to the HPC rotor 
stage 2 to 5 spool and stage 7 to 9 spool. This proposed AD would 
require removal and replacement of the affected HPC rotor stage 2 to 5 
and stage 7 to 9 spools. We are proposing this AD to prevent failure of 
the HPC rotor stage 2 to 5 and stage 7 to 9 spools, which could lead to 
uncontained engine failure and damage to the airplane.

DATES: We must receive comments on this proposed AD by December 22, 
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: 800-565-0140; email: [email protected];

[[Page 64374]]

Web site: www.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-
3713; 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-2015-3713; 
Directorate Identifier 2015-NE-23-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 non-conforming honeycomb 
seals were installed in the affected HPCs adjacent to the HPC rotor 
stage 2 to 5 spools and stage 7 to 9 spools. The honeycomb seals in the 
HPC were machined to an incorrect radial height which resulted in 
reduced clearances between the honeycomb and the rotating spools. This 
error could lead to cracks on the spools prior to reaching their full 
life. This condition, if not corrected, could result in failure of the 
HPC rotor stage 2 to 5 and stage 7 to 9 spools, 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-
327, dated July 21, 2015; and SB No. EAGP7-72-328, dated July 21, 2015. 
The SBs describe procedures for removal and replacement of HPC rotor 
stage 2 to 5 spools and HPC rotor stage 7 to 9 spools, respectively. 
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 document.

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 removal and replacement of the 
affected HPC rotor stage 2 to 5 and stage 7 to 9 spools.

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-2015-3713; Directorate Identifier 
2015-NE-23-AD.

(a) Comments Due Date

    We must receive comments by December 22, 2015.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to Engine Alliance (EA) GP7270 turbofan engines 
with one or both of the following installed:

[[Page 64375]]

    (1) A high-pressure compressor (HPC) rotor stage 2 to 5 spool, 
part number (P/N) 382-104-807-0, with a serial number (S/N) listed 
in EA Service Bulletin (SB) No. EAGP7-72-327, dated July 21, 2015; 
or
    (2) an HPC rotor stage 7 to 9 spool, P/N 2031M90G04, 2031M90G05, 
or 2031M90G07, with an S/N listed in EA SB No. EAGP7-72-328, dated 
July 21, 2015.

(d) Unsafe Condition

    This AD was prompted by reports of the installation of non-
conforming honeycomb seals in the HPC adjacent to the HPC rotor 
stage 2 to 5 spool and stage 7 to 9 spool. We are issuing this AD to 
prevent failure of the HPC rotor stage 2 to 5 spools and stage 7 to 
9 spools, 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. Within 30 days after the effective date of this 
AD or before accumulating 2,100 engine cycles since the last 
disassembly of the compressor module of the engine, whichever occurs 
later:
    (1) For engines with an HPC rotor stage 2 to 5 spool, P/N 382-
104-807-0, installed with a S/N listed in EA SB No. EAGP7-72-327, 
dated July 21, 2015, do the following:
    (i) Remove the HPC rotor stage 2 to 5 spool from service and 
replace with a part eligible for installation.
    (ii) Remove and replace the honeycomb seals on the HPC stage 5 
vanes.
    (2) For engines with an HPC rotor stage 7 to 9 spool, P/N 
2031M90G04, 2031M90G05, or 2031M90G07 installed with an S/N listed 
in EA SB No. EAGP7-72-328, dated July 21, 2015, do the following:
    (i) Remove the HPC rotor stage 7 to 9 spool from service and 
replace with a part eligible for installation.
    (ii) Remove and replace the honeycomb seals on the HPC stage 6, 
stage 7, and stage 8 vanes.

(f) 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].

(g) 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 SBs No. EAGP7-72-327, dated July 21, 2015; and No. EAGP7-
72-328, dated July 21, 2015 can be obtained from EA using the 
contact information in paragraph (g)(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: 
www.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 October 16, 2015.
Colleen M. D'Alessandro,
Directorate Manager, Engine & Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 2015-26755 Filed 10-22-15; 8:45 am]
BILLING CODE 4910-13-P