Airworthiness Directives: General Electric Co. (GE) CF6-80A Series Turbofan Engines

Federal Register: November 14, 2008 (Volume 73, Number 221)

Proposed Rules

Page 67433-67435

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

DOCID:fr14no08-38

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration 14 CFR Part 39

Docket No. FAA-2008-1206; Directorate Identifier 2008-NE-19-AD

RIN 2120-AA64

Airworthiness Directives; General Electric Co. (GE) CF6-80A

Series Turbofan Engines

AGENCY: Federal Aviation Administration (FAA), Department of

Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) for GE CF6-80A series turbofan engines with a high-pressure turbine rotor (HPTR) stage 1 disk, part number (P/N) 9367M45G06, installed.

This proposed AD would require removing any HPTR stage 1 disk, P/N 9367M45G06, before exceeding 2,075 cycles-since-new (CSN). This proposed AD results from an error by GE that incorrectly cited a cyclic life of 12,600 CSN for the HPTR stage 1 disk, P/N 9367M45G06. We are proposing this AD to prevent the HPTR stage 1 disk from exceeding its part life which could cause fatigue cracks to start and grow. These cracks could result in a possible uncontained disk failure and damage to the airplane.

DATES: We must receive any comments on this proposed AD by January 13, 2009.

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.

Page 67434

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: Robert Green, Aerospace Engineer,

Engine Certification Office, FAA, Engine & Propeller Directorate, 12

New England Executive Park, Burlington, MA 01803; e-mail: robert.green@faa.gov; telephone (781) 238-7754; 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-2008-1206; Directorate

Identifier 2008-NE-19-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 a recent GE internal audit, comparing the life-limited parts certification documents to the part life limits specified in the

Airworthiness Limitations Section of the Instructions for Continuing

Airworthiness, GE found that the life limits for the CF6-80A series engines incorrectly specified a cyclic life of 12,600 CSN for the HPTR stage 1 disk, P/N 9367M45G06. GE has determined that the correct life limit for the HPTR stage 1 disk, P/N 9367M45G06, is 2,075 CSN. Failure to remove these disks from service before exceeding the new, reduced life limit of 2,075 CSN could result in fatigue cracks, leading to a possible uncontained disk 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 from service any HPTR stage 1 disk, P/N 9367M45G06, before it exceeds 2,075 CSN.

Costs of Compliance

We estimate that this proposed AD would affect 10 engines installed on airplanes of U.S. registry. We also estimate that it would take about 110 work-hours per engine to perform the proposed actions, and that the average labor rate is $80 per work-hour. Required parts would cost about $437,000 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $4,462,000.

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 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 Co. (GE): Docket No. FAA-2008-1206; Directorate

Identifier 2008-NE-19-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by January 13, 2009.

Affected ADs

(b) None.

Applicability

(c) This AD applies to GE CF6-80A, CF6-80A1, CF6-80A2, and CF6- 80A3 turbofan engines with a high-pressure turbine rotor (HPTR) stage 1 disk, part number (P/N) 9367M45G06, installed. These engines are installed on, but not limited to, Airbus A310 series and Boeing 767 series airplanes.

Page 67435

Unsafe Condition

(d) This AD results from an error by GE that incorrectly cited a cyclic life of 12,600 CSN in the Airworthiness Limitations Section

(ALS) of the Instructions for Continued Airworthiness (ICA) for the

HPTR, P/N 9367M45G06. We are issuing this AD to prevent the HPTR stage 1 disk from exceeding its part life which could cause fatigue cracks to start and grow. These cracks could result in a possible uncontained disk failure and damage to the airplane.

Compliance

(e) You are responsible for having the actions required by this

AD performed within the compliance times specified unless the actions have already been done.

New Reduced Life Limit for HPTR Stage 1 Disks, P/N 9367M45G06

(f) After the effective date of this AD, remove HPTR stage 1 disks, P/N 9367M45G06, from service before exceeding the new, reduced life limit of 2,075 cycles-since-new.

Alternative Methods of Compliance

(g) 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.

Special Flight Permits

(h) Under 14 CFR part 39.23, we are prohibiting any special flight permits.

Related Information

(i) Contact Robert Green, Aerospace Engineer, Engine

Certification Office, FAA, Engine & Propeller Directorate, 12 New

England Executive Park, Burlington, MA 01803; e-mail: robert.green@faa.gov; telephone (781) 238-7754; fax (781) 238-7199, for more information about this AD.

Issued in Burlington, Massachusetts, on November 7, 2008.

Peter A. White,

Assistant Manager, Engine and Propeller Directorate, Aircraft

Certification Service.

FR Doc. E8-27080 Filed 11-13-08; 8:45 am

BILLING CODE 4910-13-P

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