AD 2008-06-19

This AD becomes effective April 22, 2008.

You can get the service information identified in this AD from Honeywell International Inc., 111 S. 34th St., Phoenix, AZ 85034-2802; Web site: http://portal.honeywell.com/wps/portal/aero; telephone (800) 601-3099.

The Docket Operations office is located at Docket Management Facility, U.S. Department of Transportation, 1200 New Jersey Avenue, SE., West Building Ground Floor, Room W12-140, Washington, DC 20590-0001.

Joseph Costa, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960 Paramount Blvd., Lakewood, CA 90712-4137; e-mail: joseph.costa@faa.gov; telephone: (562) 627-5246; fax: (562) 627-5210.

The FAA proposed to amend 14 CFR part 39 with a proposed AD. The proposed AD applies to Honeywell International Inc. ATF3-6 and ATF3-6A series turbofan engines equipped with a certain part numbered LPC aft shaft. We published the proposed AD in the Federal Register on October 5, 2007 (72 FR 56945). That action proposed to require removing LPC aft shafts, P/N 3002070-1, from service and installing serviceable LPC aft shafts.

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 AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Operations office (telephone (800) 647-5527) is provided in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

We provided the public the opportunity to participate in the development of this AD. We received no comments on the proposal or on the determination of the cost to the public.

We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD as proposed.

We estimate that this AD will affect 32 ATF3-6 and ATF3-6A series turbofan engines installed on airplanes of U.S. registry. We also estimate that it will take about 40 work-hours per engine to perform the actions if unscheduled, 20 work-hours per engine if during scheduled major periodic inspection (MPI), and 1 work-hour per engine during scheduled core zone inspection (CZI). We estimate that four engines would be unscheduled, 14 engines would be scheduled at MPI, and 14 engines would be scheduled at CZI. The average labor rate is $80 per work-hour. Required parts would cost about $15,000 per engine. Based on these figures, we estimate the total cost of the proposed AD to U.S. operators to be $516,320.

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: