AD 2009-12-09

This AD becomes effective July 16, 2009.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of July 16, 2009.

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

Tom Rodriguez, Aerospace Engineer, International Branch, ANM-116, Transport Airplane Directorate, FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 227-1137; fax (425) 227-1149.

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 November 26, 2008 (73 FR 71961). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states:

One ATR operator reported some spurious “Pitch disconnect” warning and “AIL and R ELEV” Anti-Ice Horn Fault caution annunciations which precluded the use of the autopilot.

During the investigation, chafed wirings were found in the rear baggage zone, closed [close] to the forward side of the aft pressure bulkhead, due to contact with an understructure securing screw. The concerned wiring harness includes rudder trim, pitch trim and stick pusher control wires. Damages on those wires might lead to the loss of fail safe criteria for those critical functions.

To address the identified unsafe condition, this AD mandates a one-time inspection and a routing modification of the electrical wires in the bulkhead area.

The unsafe condition is reduced controllability of the airplane. The corrective action also includes contacting ATR for repair instructions and doing the repair if any damage (chafing or contact between bundles of cables and the airframe structure) is found during the one-time inspection. You may obtain further information by examining the MCAI in the AD docket.

We have revised paragraph (c) of the AD to coincide with the effectivity of the European Aviation Safety Agency (EASA) AD.

ATR has issued the service bulletins identified in the following table.

These service bulletins differ from the original issues of those service bulletins, all dated February 11, 2008 (which were referenced in the NPRM), by including clarifications and editorial changes that do not affect the technical content. This AD does not require the “Additional Work” described in ATR Service Bulletins ATR42-92-0018 and ATR72-92-1018, both Revision 01, both dated September 4, 2008.

We have changed paragraphs (f)(1), (f)(2), and (f)(3) of this AD to refer to the most recent revisions of the service bulletins identified in the previous table, and added paragraph (f)(4) of this AD to give credit for actions done according to the prior issues identified in the following table.

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 with the changes described previously. We determined these changes will not increase the economic burden on any operator or increase the scope of the AD.

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 our FAA policies. Any such differences are highlighted in a NOTE within the AD.

We estimate that this AD will affect 48 products of U.S. registry. We also estimate that it will take about 5 work-hours per product to comply with the basic requirements of this AD. The average labor rate is $80 per work-hour. Required parts will cost about $131 per product. Where the service information lists required parts costs that are covered under warranty, we have assumed that there will be no charge for these parts. As we do not control warranty coverage for affected parties, some parties may incur costs higher than estimated here. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $25,488, or $531 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 the 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 Operations office 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 Operations 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: