81 FR 75684 - Airworthiness Directives; Engine Alliance Turbofan Engines

DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration

Federal Register Volume 81, Issue 211 (November 1, 2016)

We are superseding airworthiness directive (AD) 2013-02-06 for all Engine Alliance (EA) GP7270 and GP7277 turbofan engines with certain part number (P/N) high-pressure turbine (HPT) stage 2 nozzle segments installed. AD 2013-02-06 required initial and repetitive borescope inspections (BSI) and removal from service of these nozzles before further flight if one or more burn holes were detected in any HPT stage 2 nozzle segment. AD 2013-02-06 also required removal from service of these HPT stage 2 nozzle segments at the next engine shop visit. This AD requires the same inspections as AD-2013-02-06, requires removal of affected HPT stage 2 nozzles at next piece-part exposure, and adds certain P/Ns to the applicability. This AD was prompted by another report of inadequate cooling of the HPT stage 1 shroud and stage 2 nozzle, leading to damage to the HPT stage 2 nozzle, burn- through of the turbine case, and in-flight shutdown. We are issuing this AD to prevent HPT stage 2 nozzle failure, uncontrolled fire, in- flight shutdown, and damage to the airplane.

[Federal Register Volume 81, Number 211 (Tuesday, November 1, 2016)]
[Rules and Regulations]
[Pages 75684-75686]
From the Federal Register Online  [www.thefederalregister.org]
[FR Doc No: 2016-26280]


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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 39-18700; AD 2016-22-11]
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 superseding airworthiness directive (AD) 2013-02-06 for 
all Engine Alliance (EA) GP7270 and GP7277 turbofan engines with 
certain part number (P/N) high-pressure turbine (HPT) stage 2 nozzle 
segments installed. AD 2013-02-06 required initial and repetitive 
borescope inspections (BSI) and removal from service of these nozzles 
before further flight if one or more burn holes were detected in any 
HPT stage 2 nozzle segment. AD 2013-02-06 also required removal from 
service of these HPT stage 2 nozzle segments at the next engine shop 
visit. This AD requires the same inspections as AD-2013-02-06, requires 
removal of affected HPT stage 2 nozzles at next piece-part exposure, 
and adds certain P/Ns to the applicability. This AD was prompted by 
another report of inadequate cooling of the HPT stage 1 shroud and 
stage 2 nozzle, leading to damage to the HPT stage 2 nozzle, burn-
through of the turbine case, and in-flight shutdown. We are issuing 
this AD to prevent HPT stage 2 nozzle failure, uncontrolled fire, in-
flight shutdown, and damage to the airplane.

DATES: This AD is effective November 16, 2016.
    We must receive any comments on this AD by December 16, 2016.

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 by searching for and locating Docket No. FAA-2012-
1293; 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, 1200 District Avenue, Burlington, 
MA 01803; phone: 781-238-7157; fax: 781-238-7199; email: 
[email protected].

SUPPLEMENTARY INFORMATION: 

Discussion

    On January 15, 2013, we issued AD 2013-02-06, Amendment 39-17327 
(78 FR 5710, January 28, 2013), (``AD 2013-02-06''), for all Engine 
Alliance GP7270 and GP7277 turbofan engines with an HPT stage 2 nozzle, 
P/N 2101M24G01, 2101M24G02, or 2101M24G03, installed. AD 2013-02-06 
required initial and repetitive BSIs and removal from service of these 
nozzles before further flight if any burn holes were detected in the 
affected nozzles. AD 2013-02-06 also required removal from service of 
the affected nozzles at the next engine shop visit. AD 2013-02-06 
resulted from a report 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 in-flight shutdown. We issued AD 2013-02-06 to 
prevent HPT stage 2 nozzle failure, uncontrolled fire, in-flight 
shutdown, and damage to the airplane.

Actions Since AD 2013-02-06 Was Issued

    Since we issued AD 2013-02-06, we received another report of 
inadequate cooling of the HPT stage 1 shroud and stage 2 nozzle, 
leading to damage to the HPT stage 2 nozzle, burn-through of the 
turbine case, and in-flight shutdown. This event occurred with HPT 
stage 2 nozzle, P/N 2101M24G04, 2101M24G05, or 2101M24G06 installed. 
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, uncontrolled fire, in-flight 
shutdown, and damage to the airplane.

Related Service Information

    We reviewed EA Service Bulletins EAGP7-72-190, dated December 6, 
2012 and EAGP7-72-262, Revision No. 5, dated December 18, 2015. This 
service information describes procedures for inspecting the HPT stage 2 
nozzle segments.

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 BSIs of the HPT stage 1 
shroud and HPT

[[Page 75685]]

stage 2 nozzle segments and removal from service of these nozzle 
segments before further flight if one or more burn holes are detected 
on the HPT stage 2 nozzle or if the HPT stage 1 shroud is found 
distorted. This AD also requires removal from service of any HPT stage 
2 nozzle segment, P/N 2101M24G01, 2101M24G02, 2101M24G03, 2101M24G04, 
2101M24G05, or 2101M24G06, at next piece-part exposure.

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 we did not provide you with notice and an opportunity to 
provide your comments before it becomes effective. 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 will take about 
two hours per engine to perform a BSI of the HPT stage 2 nozzle. The 
average labor rate is $85 per hour. Required parts cost about $504,486 
per engine. Based on these figures, we estimate the cost of this 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 part 39 of the Federal Aviation 
Regulations (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 removing airworthiness directive (AD) 
2013-02-06, Amendment 39-17327 (78 FR 5710, January 28, 2013) and 
adding the following new AD:

2016-22-11 Engine Alliance: Amendment 39-18700; Docket No. FAA-2012-
1293; Directorate Identifier 2012-NE-45-AD.

(a) Effective Date

    This AD is effective November 16, 2016.

(b) Affected ADs

    This AD replaces AD 2013-02-06, Amendment 39-17327 (78 FR 5710, 
January 28, 2013).

(c) Applicability

    This AD applies to all Engine Alliance GP7270 and GP7277 
turbofan engines with a high-pressure turbine (HPT) stage 2 nozzle 
segment, part number (P/N) 2101M24G01, 2101M24G02, 2101M24G03, 
2101M24G04, 2101M24G05, or 2101M24G06, installed.

(d) Unsafe Condition

    This AD was prompted by a report of inadequate cooling of the 
HPT stage 1 shroud and stage 2 nozzle, leading to damage to the HPT 
stage 2 nozzle, burn-through of the turbine case, and in-flight 
shutdown. We are issuing this AD to prevent HPT stage 2 nozzle 
failure, uncontrolled fire, in-flight shutdown, and damage to the 
airplane.

(e) Compliance

    Comply with this AD within the compliance times specified, 
unless already done.
    (1) Perform a 360 degree borescope inspection of the HPT stage 1 
shroud and stage 2 nozzle as follows:
    (i) For engines with nozzles installed at a shop visit that did 
not include full engine overhaul, borescope inspect the HPT stage 1 
shroud and stage 2 nozzle as follows:
    (A) If the nozzle has fewer than 1,050 cycles-since-new (CSN) or 
cycles-since-repair (CSR) on the effective date of this AD, before 
the nozzle has accumulated 1,100 CSN or CSR.
    (B) If the nozzle has 1,050 or more CSN or CSR on the effective 
date of this AD, within the next 50 cycles.
    (ii) For all other engines, borescope inspect the HPT stage 1 
shroud and HPT stage 2 nozzle as follows:
    (A) If the nozzle has fewer than 1,450 CSN or CSR on the 
effective date of this AD, before the nozzle has accumulated 1,500 
CSN or CSR.
    (B) If the nozzle has 1,450 or more CSN or CSR on the effective 
date of this AD, within the next 50 cycles.
    (iii) Thereafter, repetitively borescope inspect the HPT stage 1 
shroud and stage 2 nozzle as follows:
    (A) For engines with HPT stage 2 nozzle segments, P/N 
2101M24G01, 2101M24G02, or 2101M24G03, within every 150 additional 
cycles-in-service (CIS).
    (B) For engines with HPT stage 2 nozzle segments, P/N 
2101M24G04, 2101M24G05, or 2101M24G06, within every 300 additional 
CIS.
    (2) If any burn holes are detected through the surface of the 
nozzle or if the shroud is distorted radially inward with evidence 
of blade tip rubs, remove the HPT stage 1 shroud and HPT stage 2 
nozzle from service before further flight.

[[Page 75686]]

(f) Mandatory Terminating Action

    Replace HPT stage 2 nozzle segments, P/N 2101M24G01, 2101M24G02, 
2101M24G03, 2101M24G04, 2101M24G05, and 2101M24G06, at the next 
piece-part exposure, with parts eligible for installation.

(g) Definition

    For the purpose of this AD, piece-part exposure is when the HPT 
stage 2 nozzle is removed from the engine and completely 
disassembled.

(h) Alternative Methods of Compliance (AMOCs)

    The Manager, Engine Certification Office, FAA, 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].

(i) Related Information

    For more information about this AD, contact Martin Adler, 
Aerospace Engineer, Engine & Propeller Directorate, FAA, 1200 
District Avenue, Burlington, MA 01803; phone: 781-238-7157; fax: 
781-238-7199; email: [email protected].

(j) Material Incorporated by Reference

    None.

    Issued in Burlington, Massachusetts, on October 25, 2016.
Colleen M. D'Alessandro,
Manager, Engine & Propeller Directorate, Aircraft Certification 
Service.
[FR Doc. 2016-26280 Filed 10-31-16; 8:45 am]
 BILLING CODE 4910-13-P