AD 2008-16-19

This AD becomes effective September 17, 2008.

On September 17, 2008, the Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD.

You may examine the AD docket on the Internet at http://www.regulations.gov or in person at Document Management Facility, U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.

Doug Rudolph, Aerospace Engineer, FAA, Small Airplane Directorate, 901 Locust, Room 301, Kansas City, Missouri 64106; telephone: (816) 329-4059; fax: (816) 329-4090.

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to the specified products. That NPRM was published in the Federal Register on June 9, 2008 (73 FR 32497). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

This Airworthiness Directive (AD) is prompted due to the discovery of loose self-locking stop nuts Part Number (P/N) 938.07.65.105 in the tail landing gear fastener assemblies of some PC-6 aircraft.

It is believed that this occurrence could also exist in other fastener assemblies using nuts P/N 938.07.65.105 at various identified locations in the aircraft.

If left uncorrected, the identified assemblies may become loose and not function as designed and could lead to hazardous situations.

In order to prevent those conditions, the present AD requires you to replace self-locking stop nuts P/N 938.07.65.105 from the Tail Landing Gear Assembly, the Parachute Cable Assembly, the Water Tank Assembly, the Cable Tensioner Assembly, the Fuel Filter Assembly, the Hydraulic Pump Assembly and the Engine Mounts Assembly in accordance with Pilatus PC-6 Service Bulletin No. 53-002 Revision 2.

We gave the public the opportunity to participate in developing this AD. We received no comments on the NPRM or on the determination of the cost to the public.

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

We have reviewed the MCAI and related service information and, in general, agree with their substance. But we might have found it necessary to use different words from those in the MCAI to ensure the AD is clear for U.S. operators and is enforceable. In making these changes, we do not intend to differ substantively from the information provided in the MCAI and related service information.

We might also have required different actions in this AD from those in the MCAI in order to follow FAA policies. Any such differences are highlighted in a NOTE within the AD.

Based on the service information, we estimate that this AD will affect 50 products of U.S. registry. We also estimate that it will take about 7 work-hours per product to comply with basic requirements of this AD. The average labor rate is $80 per work-hour. Required parts will cost about $310 per product.

Based on these figures, we estimate the cost of this AD to the U.S. operators to be $43,500, or $870 per product.

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 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 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 regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD Docket.

You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains the NPRM, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (telephone (800) 647-5527) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

Accordingly, under the authority delegated to me by the Administrator, the FAA 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 AD: