AD 2005-13-07

This AD becomes effective July 27, 2005. The Director of the Federal Register approved the incorporation by reference of certain publications listed in the regulations as of July 27, 2005.

You can get the service information identified in this AD from Honeywell Engines and Systems (formerly AlliedSignal Inc. and Garrett Turbine Engine Co.) Technical Publications and Distribution, M/S 2101-201, P.O. Box 52170, Phoenix, AZ 85072-2170; telephone: (602) 365-2493 (General Aviation), (602) 365-5535 (Commercial Aviation), fax: (602) 365-5577 (General Aviation), (602) 365-2832 (Commercial Aviation).

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.

Joseph Costa, Aerospace Engineer, Los Angeles Aircraft Certification Office, FAA, Transport Airplane Directorate, 3960 Paramount Blvd., Lakewood CA 90712-4137; 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. (formerly AlliedSignal Inc. and Garrett Turbine Engine Co.) TFE731-2 and -3 series turbofan engines with certain P/Ns and SNs of LP 1st and 2nd stage turbine rotor discs initially installed as new parts before April 1, 1991. These discs were heat treated with a process that may have resulted in disk material with a non-uniform microstructure that is susceptible to creep fatigue, which may lead to cracking or separation. We published the proposed AD in the Federal Register on July 1, 2004 (69 FR 39875). That action proposed to require replacement of those LP 1st and 2nd stage turbine rotor discs.

You may examine the docket that contains the AD, any comments received, and any final disposition in person at the DMS Docket Offices 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 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.

There are about 56 Honeywell International Inc. TFE731-2 and -3 series turbofan engines of the affected design in the worldwide fleet. We estimate that 24 engines installed on airplanes of U.S. registry will be affected by this AD. We also estimate that it will take about 4 work hours per engine to perform these actions, and that the average labor rate is $65 per work hour. Required parts cost about $30,000 per engine. Based on these figures, we estimate the total cost of this AD to U.S. operators to be $726,240.

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: