[Federal Register Volume 78, Number 26 (Thursday, February 7, 2013)]
[Proposed Rules]
[Pages 9003-9005]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-02721]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2012-1329; Directorate Identifier 2012-NE-46-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 GP7270 and GP7277 turbofan engines. This
proposed AD was prompted by damage to the high-pressure compressor
(HPC) stage 7-9 spool caused by failure of the baffle plate feature on
affected HPC stage 6 disks. This proposed AD would require initial and
repetitive borescope inspections of the baffle plate feature and
removal from service of the HPC stage 6 disk before further flight, if
the plate is missing material. This proposed AD would also require
mandatory removal from service of these HPC stage 6 disks at the next
HPC module exposure. We are proposing this AD to prevent uncontained
failure of the HPC stage 7-9 spool, uncontained engine failure, and
damage to the airplane.
DATES: We must receive comments on this proposed AD by April 8, 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: 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, 411 Silver Lane, East Hartford, CT 06118, phone: 800-
565-0140; Web site: https://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.
[[Page 9004]]
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 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-2012-1329;
Directorate Identifier 2012-NE-46-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 received reports of the baffle plate feature failing on HPC
stage 6 disks, part number (P/N) 382-100-505-0 from high cycle fatigue.
The failures resulted in material from the baffle plate feature causing
damage to the HPC stage 7-9 spool, causing the spool to crack. Engine
Alliance has introduced a redesigned HPC stage 6 disk with a different
P/N, to eliminate the failures. This condition, if not corrected, could
result in uncontained failure of the HPC stage 7-9 spool, uncontained
engine failure, and damage to the airplane.
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 initial and repetitive borescope
inspections of the HPC stage 6 disk baffle plate feature and removal
from service of any HPC stage 6 disk, P/N 382-100-505-0, before further
flight if the feature is missing any material. This proposed AD would
also require mandatory removal from service of these HPC stage 6 disks
at the next HPC module exposure, but no later than accumulating 6,800
cycles-since-new on the disk.
Costs of Compliance
We estimate that this proposed AD would affect no engines installed
on airplanes of U.S. registry, and the cost 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
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-2012-1329; Directorate Identifier
2012-NE-46-AD.
(a) Comments Due Date
We must receive comments by April 8, 2013.
(b) Affected ADs
None.
(c) Applicability
This AD applies to Engine Alliance GP7270 and GP7277 turbofan
engines with a high-pressure compressor (HPC) stage 6 disk, part
number (P/N) 382-100-505-0, installed.
(d) Unsafe Condition
This AD was prompted by damage to the HPC stage 7-9 spool caused
by failure of the baffle plate feature on affected HPC stage 6
disks. We are issuing this AD to prevent uncontained failure of the
HPC stage 7-9 spool, uncontained engine failure, and damage to the
airplane.
(e) Compliance
Comply with this AD within the compliance times specified,
unless already done.
(f) Borescope Inspections
(1) For HPC stage 6 disks with fewer than 1,000 cycles-since-new
(CSN) on the effective date of this AD, initially borescope inspect
the baffle plate feature on the disk (360 degrees) before
accumulating 1,500 CSN.
(2) For HPC stage 6 disks with 1,000 CSN or more on the
effective date of this AD, initially borescope inspect the baffle
plate feature on the disk (360 degrees) within the next 500 cycles-
in-service (CIS).
[[Page 9005]]
(3) Thereafter, repetitively borescope inspect the baffle plate
feature on the disk (360 degrees) within every 500 CIS.
(4) Remove the HPC stage 6 disk before further flight if found
cracked or with missing material.
(g) Mandatory Removal From Service of Affected HPC Stage 6 Disks
At next HPC module exposure, but not to exceed 6,800 CSN on the
HPC stage 6 disk, remove the HPC stage 6 disk, P/N 382-100-505-0,
from service.
(h) Installation Prohibition
After the effective date of this AD, do not install any HPC
stage 6 disk, P/N 382-100-505-0, into any HPC module.
(i) Definition
For the purpose of this AD, HPC module exposure is defined as
separation of the flanges between the compressor case and the
combustion diffuser case.
(j) 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.
(k) 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) Engine Alliance Service Bulletin No. EAGP7-72-236, pertains
to the subject of this AD.
(3) For service information identified in this AD, contact
Engine Alliance, 411 Silver Lane, East Hartford, CT 06118, phone:
800-565-0140; Web site: https://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.
Issued in Burlington, Massachusetts, on January 28, 2013.
Robert J. Ganley,
Acting Manager, Engine & Propeller Directorate, Aircraft Certification
Service.
[FR Doc. 2013-02721 Filed 2-6-13; 8:45 am]
BILLING CODE 4910-13-P