AD 2007-11-20

This AD becomes effective July 10, 2007. The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of July 10, 2007.

You can get the service information identified in this AD from General Electric Company via Lockheed Martin Technology Services, 10525 Chester Road, Suite C, Cincinnati, Ohio 45215, telephone (513) 672-8400, fax (513) 672-8422.

You may examine the AD docket on the Internet at http://dms.dot.gov or in Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC.

James Lawrence, Aerospace Engineer, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803; e-mail: james.lawrence@faa.gov; telephone: (781) 238-7176, fax: (781) 238-7199.

The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to GE CF6-80 series turbofan engines with fuel shroud retaining rings, part number (P/N) J204P0084, installed. We published the proposed AD in the Federal Register on February 15, 2007 (72 FR 7355). That action proposed to require replacing those retaining rings with a more robust design fuel shroud retaining snap ring.

You may examine the docket that contains the AD, 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 (800) 647-5227) 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 DMS receives them.

We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.

One commenter, GE, states that the Table 1 compliance schedule in the proposed AD is somewhat difficult to follow. The commenter states that the table needs lines or spaces added, to separate some of the items in it, for clarity.

We agree that the Table 1 compliance schedule in the proposed AD is difficult to follow. We have deleted the Table 1 compliance schedule from this AD, based on comments received on the proposed AD, and which are discussed in the paragraphs that follow.

GE requests that we reduce the AD applicability to only engines with the drainless manifold configuration, since the drained manifold configuration is not subjected to high internal pressure. If a fuel supply tube leaks internally, the shroud contains the fuel, preventing an external leak. We agree and reduced the AD applicability in the AD to only engines with the drainless manifold configuration.

GE requests that we clarify the applicability to state that engines built at the factory during production assembly with the drainless manifold configuration, are also subject to the requirements of the AD. We agree and made that clarification in the AD.

GE suggests that we add a note or statement to the compliance section verifying that CF6-80C2 series engine operators that have complied with a previous revision of SB No. CF6-80C2 S/B 73-0337, are in compliance with the AD. We agree. We added the “SB Compliance Credit for CF6-80C2 Series Engines” paragraph to the AD.

KLM Royal Dutch Airlines requests that we revise the section of the compliance that states “Comply with this AD as soon as one or more fuel shroud retaining rings are removed from the engine” to, “Comply with this AD during next engine shop visit for any reason.” The commenter states that the AD action should be only at engine-level and not on-wing.

We agree that the AD action should be only at engine-level and not on-wing. That part of the proposed compliance section was for engines that had not incorporated GE SB No. CF6-80C2 S/B 73-0253 (which eliminates the fuel drain system manifold and introduces a new drainless fuel manifold). The result is that this AD now applies to only the drainless manifold configuration. In addition, we deleted the Table 1 compliance schedule because it is no longer needed, clarified compliance paragraph (g), and clarified applicability paragraphs (c) and (d) in this AD.

All Nippon Airways requests that we change the proposed AD nomenclature for the rings being removed, from “retaining snap ring” to “retaining ring”. We agree. We confirmed that GE's SBs refer to the removed rings as “retaining rings” and to the rings being installed as “snap rings.” We changed the nomenclature in the AD to reflect that which the SBs use.

For reference, we added a Table under paragraph (f) which lists fuel manifold production part numbers.

We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

We estimate that this AD will affect 853 CF6-80 series turbofan engines installed on airplanes of U.S. registry. We also estimate that it will take about 12.5 work-hours per engine to perform the actions, and that the average labor rate is $80 per work-hour. Required parts will cost about $72 per engine. Based on these figures, we estimate the total cost of the AD to U.S. operators to be $914,416.

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.

We have determined that 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); and

(3) 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.

We prepared a summary of the costs to comply with this AD and placed it in the AD Docket. You may get a copy of this summary at the address listed under ADDRESSES.

Accordingly, under the authority delegated to me by the Administrator, the Federal Aviation Administration amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

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