[Federal Register: September 4, 2008 (Volume 73, Number 172)]
[Proposed Rules]
[Page 51604-51605]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr04se08-11]
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Proposed Rules
Federal Register
________________________________________________________________________
This section of the FEDERAL REGISTER contains notices to the public of
the proposed issuance of rules and regulations. The purpose of these
notices is to give interested persons an opportunity to participate in
the rule making prior to the adoption of the final rules.
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[[Page 51604]]
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. FAA-2008-0827; Directorate Identifier 2008-NE-26-AD]
RIN 2120-AA64
Airworthiness Directives; General Electric Company (GE) CF6-80A
Series Turbofan Engines
AGENCY: Federal Aviation Administration (FAA), Department of
Transportation (DOT).
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD)
for GE CF6-80A series turbofan engines with certain stage 1 high-
pressure turbine (HPT) rotor disks, installed. This proposed AD would
require removal from service of those stage 1 HPT rotor disks within 30
days after the effective date of the AD. This proposed AD results from
the FAA learning that those disks are susceptible to cracks developing
in the bottoms of the dovetail slots. We are proposing this AD to
prevent cracks developing in the bottoms of the dovetail slots that
could propagate to a failure of the disk and cause an uncontained
engine failure and damage to the airplane.
DATES: We must receive any comments on this proposed AD by November 3,
2008.
ADDRESSES: Use one of the following addresses to comment on this
proposed AD.
Federal eRulemaking Portal: Go to http://
www.regulations.gov and follow the instructions for sending your
comments electronically.
Mail: Docket Management Facility, U.S. Department of
Transportation, 1200 New Jersey Avenue, SE., West Building Ground
Floor, Room W12-140, Washington, DC 20590-0001.
Hand Delivery: Deliver to mail address above between 9
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
Fax: (202) 493-2251.
FOR FURTHER INFORMATION CONTACT: Tara Chaidez, Aerospace Engineer,
Engine Certification Office, FAA, Engine and Propeller Directorate, 12
New England Executive Park, Burlington, MA 01803; e-mail:
tara.chaidez@faa.gov; telephone: (781) 238-7773, fax: (781) 238-7199.
SUPPLEMENTARY INFORMATION:
Comments Invited
We invite you to send us any written relevant data, views, or
arguments regarding this proposal. Send your comments to an address
listed under ADDRESSES. Include ``Docket No. FAA-2008-0827; Directorate
Identifier 2008-NE-26-AD'' in the subject line of your comments. We
specifically invite comments on the overall regulatory, economic,
environmental, and energy aspects of the proposed AD. We will consider
all comments received by the closing date and may amend the proposed AD
in light 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
with FAA personnel concerning this proposed AD. Using the search
function of the Web site, anyone can find and read the comments in any
of our dockets, including, if provided, the name of the individual who
sent the comment (or signed the comment on behalf of an association,
business, labor union, etc.). You may review the DOT's complete Privacy
Act Statement in the Federal Register published on April 11, 2000 (65
FR 19477-78).
Examining the AD Docket
You may examine the AD docket on the Internet at http://
www.regulations.gov; or in person at the Docket Operations office
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 Operations office (telephone (800) 647-5527) is
the same as the Mail address provided in the ADDRESSES section.
Comments will be available in the AD docket shortly after receipt.
Discussion
During discussions with GE, we recently learned that a population
of stage 1 HPT rotor disks thought previously to have been retired, may
still be in service. These disks are subject to cracks developing in
the bottoms of the dovetail slots that could propagate to a failure of
the disk. These stage 1 HPT rotor disks, part numbers (P/Ns)
1380M69G01/G02/G04/G05/G06; 9234M67G12/G13/G14/G15/G16; 9362M58G04; and
9367M45G01/G03/G05/G06/G07/G08 are not subject to rework or initial
inspection. This proposed AD would require that all affected stage 1
HPT rotor disks be removed from service within 30 days after the
effective date of the AD. This condition, if not corrected, could
result in cracks developing in the bottoms of the dovetail slots that
could propagate to a failure of the disk and cause an uncontained
engine failure and damage to the airplane.
FAA's Determination and Requirements of the Proposed AD
We have evaluated all pertinent information and identified an
unsafe condition that is likely to exist or develop on other products
of this same type design. We are proposing this AD, which would require
removing the affected stage 1 HPT rotor disks from service within 30
days after the effective date of the AD.
Costs of Compliance
We estimate that this proposed AD would affect 3 out of 316 CF6-80A
series turbofan engines installed on airplanes of U.S. registry. We
also estimate that it would take about 1 work-hour per engine to
perform the proposed actions, and that the average labor rate is $80
per work-hour. Required parts would cost about $300,000 per engine.
Based on these figures, we estimate the total cost of the proposed AD
to U.S. operators to be $900,240.
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
[[Page 51605]]
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 have 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 that the proposed AD:
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); and
3. Would not have a significant economic impact, positive or
negative, on a substantial number of small entities under the criteria
of the Regulatory Flexibility Act.
We prepared a regulatory evaluation of the estimated costs to
comply with this proposed AD. You may get a copy of this summary at the
address listed under ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Under the authority delegated to me by the Administrator, the
Federal Aviation Administration proposes to amend 14 CFR part 39 as
follows:
PART 39--AIRWORTHINESS DIRECTIVES
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]
2. The FAA amends Sec. 39.13 by adding the following new
airworthiness directive:
General Electric Company: Docket No. FAA-2008-0827; Directorate
Identifier 2008-NE-26-AD.
Comments Due Date
(a) The Federal Aviation Administration (FAA) must receive
comments on this airworthiness directive (AD) action by November 3,
2008.
Affected ADs
(b) None.
Applicability
(c) This AD applies to General Electric Company (GE) CF6-80A
series turbofan engines with any of the following stage 1 high-
pressure turbine (HPT) rotor disk part numbers (P/Ns), installed:
(1) 1380M69G01; 1380M69G02; 1380M69G04; 1380M69G05; or
1380M69G06; or
(2) 9234M67G12; 9234M67G13; 9234M67G14; 9234M67G15; or
9234M67G16; or
(3) 9362M58G04; or
(4) 9367M45G01; 9367M45G03; 9367M45G05; 9367M45G06; 9367M45G07;
or 9367M45G08.
(d) These CF6-80A series turbofan engines are installed on, but
not limited to, Airbus A310-200 series and Boeing 767-200 series
airplanes.
Unsafe Condition
(e) This AD results from the FAA learning that those discs are
susceptible to cracks developing in the bottoms of the dovetail
slots. We are issuing this AD to prevent cracks developing in the
bottoms of the dovetail slots that could propagate to a failure of
the disk and cause an uncontained engine failure and damage to the
airplane.
Compliance
(f) You are responsible for having the actions required by this
AD performed within 30 days after the effective date of this AD,
unless the actions have already been done.
(g) Remove from service HPT stage 1 rotor disks identified by P/
N in paragraph (c) of this AD.
Prohibition of HPT Stage 1 Rotor Disks
(h) After the effective date of this AD, do not install any of
the HPT stage 1 rotor disks, listed by P/N in paragraph (c) of this
AD into any engine.
Alternative Methods of Compliance
(i) The Manager, Engine Certification Office, has the authority
to approve alternative methods of compliance for this AD, if
requested using the procedures found in 14 CFR 39.19.
Related Information
(j) Contact Tara Chaidez, Aerospace Engineer, Engine
Certification Office, FAA, Engine and Propeller Directorate, 12 New
England Executive Park, Burlington, MA 01803; e-mail:
tara.chaidez@faa.gov; telephone: (781) 238-7773, fax: (781) 238-
7199, for more information about this AD.
Issued in Burlington, Massachusetts, on August 28, 2008.
Marc J. Bouthillier,
Acting Manager, Engine and Propeller Directorate, Aircraft
Certification Service.
[FR Doc. E8-20497 Filed 9-3-08; 8:45 am]
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