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[Federal Register Volume 78, Number 18 (Monday, January 28, 2013)]
[Rules and Regulations]
[Pages 5710-5712]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-01552]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2012-1293; Directorate Identifier 2012-NE-45-AD; 
Amendment 39-17327; AD 2013-02-06]
RIN 2120-AA64

Airworthiness Directives; Engine Alliance Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; request for comments.

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SUMMARY: We are adopting a new airworthiness directive (AD) for all 
Engine Alliance GP7270 and GP7277 turbofan engines. This AD requires 
initial and repetitive borescope inspections and removal from service 
before further flight if one or more burn holes are detected, in 
certain high-pressure turbine (HPT) stage 2 nozzles. This AD also 
requires mandatory removal from service of these HPT stage 2 nozzles at 
the next engine shop visit. This AD was prompted by a report received 
of inadequate cooling of the HPT stage 2 nozzle, leading to damage to 
the HPT stage 2 nozzle, burn-through of the turbine case, and engine 
shutdown. We are issuing this AD to prevent HPT stage 2 nozzle failure, 
leading to uncontrolled fire, engine shutdown, and damage to the 
airplane.

DATES: This AD is effective February 12, 2013.
    We must receive comments on this AD by March 14, 2013.

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: U.S. Department of Transportation, Docket 
Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New 
Jersey Avenue SE., Washington, DC 20590, between 9 a.m. and 5 p.m., 
Monday through Friday, except Federal holidays.

Examining the AD Docket

    You may examine the AD docket on the Internet at http://www.regulations.gov; 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 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: 
martin.adler@faa.gov.

SUPPLEMENTARY INFORMATION:

Discussion

    We received a report of an engine shutdown and turbine case burn-
through, preceded by exceedance of the engine exhaust gas temperature 
(EGT) limit and loss of engine oil. Investigation revealed that the 
event was caused by damage to the HPT stage 2 nozzle due to inadequate 
part cooling. HPT stage 2 nozzles, part numbers (P/Ns) 2101M24G01, 
2101M24G02, and 2101M24G03, are identified as having

[[Page 5711]]

the inadequate cooling design. This condition, if not corrected, could 
result in HPT stage 2 nozzle failure, leading to uncontrolled fire, 
engine shutdown, and damage to the airplane.

FAA's Determination

    We are issuing 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.

AD Requirements

    This AD requires initial and repetitive borescope inspections and 
removal from service before further flight if burn holes are detected, 
in HPT stage 2 nozzles, P/Ns 2101M24G01, 2101M24G02, and 2101M24G03. 
This AD also requires mandatory removal from service of these HPT stage 
2 nozzles at the next engine shop visit.

FAA's Justification and Determination of the Effective Date

    No domestic operators use this product. Therefore, we find that 
notice and opportunity for prior public comment are unnecessary, and 
that good cause exists for making this amendment effective in less than 
30 days.

Comments Invited

    This AD is a final rule that involves requirements affecting flight 
safety and was not preceded by notice and an opportunity for public 
comment. However, we invite you to send any written data, views, or 
arguments about this AD. Send your comments to an address listed under 
the ADDRESSES section. Include the Docket Number FAA-2012-1293 and 
Directorate Identifier 2012-NE-45-AD at the beginning of your comments. 
We specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of this AD. We will consider all 
comments received by the closing date and may amend this 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 AD.

Costs of Compliance

    We estimate that this AD will affect no engines installed on 
airplanes of U.S. registry. We also estimate that it would take about 
two hours per engine to perform a borescope inspection of the HPT stage 
2 nozzle. The average labor rate is $85 per work hour. Required parts 
would cost about $487,312 per engine. Based on these figures, we 
estimate the cost of this proposed AD to 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

    This AD will not have federalism implications under Executive Order 
13132. This AD will 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 that this AD:
    (1) Is not a ``significant regulatory action'' under Executive 
Order 12866,
    (2) Is not a ``significant rule'' under 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.

Adoption of the Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA amends 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):

2013-02-06 Engine Alliance: Amendment 39-17327; Docket No. FAA-2012-
1293; Directorate Identifier 2012-NE-45-AD.

(a) Effective Date

    This AD is effective February 12, 2013.

(b) Affected ADs

    None.

(c) Applicability

    This AD applies to all Engine Alliance GP7270 and GP7277 
turbofan engines with a high-pressure turbine (HPT) stage 2 nozzle, 
part number (P/N) 2101M24G01, 2101M24G02, or 2101M24G03, installed.

(d) Unsafe Condition

    This AD was prompted by a report received of inadequate cooling 
of the HPT stage 2 nozzle, leading to damage to the HPT stage 2 
nozzle, burn-through of the turbine case, and engine shutdown. 
Investigation revealed that the event was caused by damage to the 
HPT stage 2 nozzle due to inadequate part cooling. We are issuing 
this AD to prevent HPT stage 2 nozzle failure, leading to 
uncontrolled fire, engine shutdown, and damage to the airplane.

(e) Compliance

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

(f) Borescope Inspections of the HPT Stage 2 Nozzle

    (1) Initially borescope inspect (360 degrees) the HPT stage 2 
nozzle at the following:
    (i) Before accumulating 1,500 cycles-since-new (CSN), if the 
nozzle has fewer than 1,450 CSN on the effective date of this AD.
    (ii) Within the next 50 cycles, if the nozzle has 1,450 or more 
CSN on the effective date of this AD.
    (2) Thereafter, repetitively borescope inspect (360 degrees) the 
HPT stage 2 nozzle within every 100 additional cycles-in-service.
    (3) If during any inspection required by this AD, any burn holes 
are detected through the surface of the nozzle, remove the nozzle 
from service before further flight.

(g) Mandatory Removal From Service of the HPT Stage 2 Nozzles

    At the next engine shop visit, remove HPT stage 2 nozzles P/N 
2101M24G01, 2101M24G02, and 2101M24G03 from service.

(h) Definition

    For the purpose of this AD, an ``engine shop visit'' is the 
induction of an engine into the shop for maintenance involving the 
separation of pairs of major mating engine

[[Page 5712]]

flanges except that the separation of engine flanges solely for the 
purposes of transportation without subsequent engine maintenance 
does not constitute an engine shop visit.

(i) 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.

(j) Related Information

    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: martin.adler@faa.gov.

(k) Material Incorporated by Reference

    None.

    Issued in Burlington, Massachusetts, on January 15, 2013.
Thomas A. Boudreau,
Acting Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2013-01552 Filed 1-25-13; 8:45 am]
BILLING CODE 4910-13-P
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