E7-2625. Airworthiness Directives; General Electric Company (GE) CF6-80 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 CF6-80 series turbofan engines having fuel shroud retaining snap rings, part number (P/N) J204P0084, installed. This proposed AD would require replacing those snap rings with a more robust design snap ring. This proposed AD results from two events of external engine fuel leakage and a subsequent under-cowl engine fire. We are proposing this AD to prevent an under-cowl engine fire and damage to the airplane during a high engine vibration event.

DATES:

We must receive any comments on this proposed AD by April 16, 2007.

ADDRESSES:

Use one of the following addresses to comment on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility; U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, Washington, DC 20590-0001.
• Fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

You can get the service information identified in this proposed AD from General Electric Company via Lockheed Martin Technology Services, 10525 Chester Road, Suite C, Cincinnati, Ohio 45215, telephone [phone], fax [phone].

You may examine the comments on this proposed AD in the AD docket on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT:

James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; telephone: [phone], fax: [phone].

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-2006-26488; Directorate Identifier 2006-NE-43-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://dms.dot.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 DOT Web site, anyone can find and read the comments in any of our dockets, including 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) or you may visit http://dms.dot.gov.

Examining the AD Docket

You may examine the docket that contains the proposal, any comments received and, any final disposition in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Office (telephone [phone]) is located on the plaza level of the Department of Transportation Nassif Building at the street address stated in ADDRESSES. Comments will be available in the AD docket shortly after the Docket Management Facility receives them.

Discussion

In October 2002 and December 2005, in two CF6-80 series turbofan engine events, a fuel manifold broke due to high engine vibration. The resulting manifold break causes a condition where the leaking fuel pressure overcomes the restraining capability of the fuel shroud retaining snap ring. The fuel pressure forces the broken fuel manifold past the sealing capability of the fuel shroud. This leads to the fuel manifold unseating from the fuel shroud, causing external engine fuel leakage and a subsequent under-cowl engine fire. This condition, if not corrected, could result in under-cowl engine fires and damage to the airplane during a high engine vibration event.

Relevant Service Information

We have reviewed and approved the technical contents of GE Service Bulletin (SB) No. CF6-80C2 S/B 73-0337, Revision 3, dated February 5, 2007, and GE SB No. CF6-80E1 S/B 73-0075, Revision 1, dated November 27, 2006. These SBs describe procedures for replacing fuel shroud retaining snap rings, P/N J204P0084, with a more robust design fuel shroud snap ring, P/N 2186M12P01 designed to withstand fuel pressure from broken fuel manifolds.

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 replacing fuel shroud retaining snap rings, P/N J204P0084, with fuel shroud retaining snap rings, P/N 2186M12P01. The proposed AD would require you to use the service information described previously to perform these actions.

Costs of Compliance

We estimate that this proposed AD would affect 853 CF6-80 series turbofan engines installed on airplanes of U.S. registry. We also estimate that it would take about 12.5 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 $72 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $914,416.

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. See the ADDRESSES section for a location to examine the regulatory evaluation.

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.

§ 39.13

[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive:

General Electric Company: Docket No. FAA-2006-26488; Directorate Identifier 2006-NE-43-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this airworthiness directive (AD) action by April 16, 2007.

Affected ADs

(b) None.

Applicability

(c) This AD applies to the following General Electric Company (GE) turbofan engines having one or more fuel shroud retaining snap rings, part number (P/N) J204P0084, installed:

CF6-80C2A1	CF6-80C2B1F
CF6-80C2A2	CF6-80C2B2F
CF6-80C2A3	CF6-80C2B4F
CF6-80C2A5	CF6-80C2B5F
CF6-80C2A8	CF6-80C2B6F
CF6-80C2A5F	CF6-80C2B6FA
CF6-80C2B1	CF6-80C2B7F
CF6-80C2B2	CF6-80C2B8F
CF6-80C2B4	CF6-80C2D1F
CF6-80C2B6	CF6-80C2L1F

(d) This AD also applies to GE CF6-80E1A1, CF6-80E1A2, CF6-80E1A3, CF6-80E1A4, and CF6-80E1A4B turbofan engines that have incorporated GE Service Bulletin (SB) No. CF6-80E1 S/B 73-0026, having one or more fuel shroud retaining snap rings, P/N J204P0084, installed.

(e) These engines are installed on, but not limited to, Airbus A300, A310, A330, Boeing 747, 767, and McDonnell Douglas MD11 airplanes.

Unsafe Condition

(f) This AD results from two events of external engine fuel leakage and a subsequent under-cowl engine fire. We are issuing this AD to prevent an under-cowl engine fire and damage to the airplane during a high engine vibration event.

Compliance

(g) You are responsible for having the actions required by this AD performed at the applicable time specified in the following Table 1 compliance schedule, unless the actions have already been done.

Table 1.—Compliance Schedule

If:	Then:
The engine is listed in paragraph (c) of this AD, and has incorporated GE SB No. CF6-80C2 S/B 73-0253 (which eliminates the fuel drain system manifold and introduces a new drainless fuel manifold)	Comply with this AD at the next engine shop visit for any reason after the effective date of this AD.
The engine is listed in paragraph (c) of this AD, and has not incorporated GE SB No. CF6-80C2 S/B 73-0253	Comply with this AD as soon as one or more fuel shroud retaining snap rings are removed from the engine.
The engine is listed in paragraph (d) of this AD, and has not incorporated GE SB No. CF6-80E1 S/B 73-0026 (which eliminates the fuel drain system manifold and introduces a new drainless fuel manifold)	Then no action is required.
The engine is listed in paragraph (d) of this AD, and has incorporated GE SB No. CF6-80E1 S/B 73-0026	Comply with this AD at the next engine shop visit for any reason after the effective date of this AD.

Replacement of Fuel Shroud Retaining Snap Rings

(h) Replace any fuel shroud retaining snap rings, P/N J204P0084, with a fuel shroud retaining snap ring, P/N 2186M12P01. Each engine has a total of 30 snap rings installed.

(i) For CF6-80C2 series engines, use paragraphs 3.A. through 3.C.(1)(b)2, of GE SB No. CF6-80C2 S/B 73-0337, Revision 3, dated February 5, 2007, to do the replacements.

(j) For CF6-80E1 series engines, use paragraphs 3.A. through 3.C.(1)(b)2, of GE SB No. CF6-80E1 S/B 73-0075, Revision 1, dated November 27, 2006, to do the replacements.

Alternative Methods of Compliance

(k) 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

(l) Contact James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; telephone [phone]; fax [phone]; e-mail: [e-mail] for more information about this AD.

Issued in Burlington, Massachusetts, on February 9, 2007.

Peter A. White,

Acting Manager, Engine and Propeller Directorate, Aircraft Certification Service.