ACTION: Final rule.

SUMMARY: We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: 

This Airworthiness Directive (AD) is issued following the discovery of a risk of chafing between an electrical feeder bundle and a bus bar under the circuit breaker panel. Most of the time, this possible chafing would be dormant and would lead to an uneventful loss of segregation within the different electrical system components. However, missing segregation combined with additional electrical failures may impair flight safety. 
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Chafing between an electrical feeder bundle and a bus bar under the circuit breaker panel could lead to electrical arcing, which could result in smoke and fire in the cockpit. We are issuing this AD to require actions to correct the unsafe condition on these products. 

DATES: This AD becomes effective June 12, 2008. 

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of June 12, 2008. 

ADDRESSES: 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. 

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

SUPPLEMENTARY INFORMATION: 

Discussion 

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 February 5, 2008 (73 FR 6620). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states: 

This Airworthiness Directive (AD) is issued following the discovery of a risk of chafing between an electrical feeder bundle and a bus bar under the circuit breaker panel. Most of the time, this possible chafing would be dormant and would lead to an uneventful loss of segregation within the different electrical system components. However, missing segregation combined with additional electrical failures may impair flight safety. 

This AD mandates inspection of the electrical feeder bundle, and modification of its routing under the circuit breaker panel through implementation of modification M3093. 

Chafing between an electrical feeder bundle and a bus bar under the circuit breaker panel could lead to electrical arcing, which could result in smoke and fire in the cockpit. 

The corrective action includes repairing or replacing damaged wiring; re-routing the feeder cables above the wiring of the "Avionic Master'' and "Aux Bat'' relays; installing a protective sheath on the feeder cables; adding spacers to separate the bus bar wiring assemblies from the feeder cables; and adding Teflon protection on the feeder cables and securing the feeder cables with wiring retaining strips. You may obtain further information by examining the MCAI in the AD docket. 

Comments 

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. 

Conclusion 

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

Differences Between This AD and the MCAI or Service Information 

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. 

Costs of Compliance 

We estimate that this AD will affect about 76 products of U.S. registry. We also estimate that it will take about 12 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 $0 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 $72,960, or $960 per product. 

Authority for This Rulemaking 

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. 

Regulatory Findings 

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. 

Examining 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. 

List of Subjects in 14 CFR Part 39 

Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. 

Adoption of the Amendment 

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

PART 39--AIRWORTHINESS DIRECTIVES 

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

Authority: 49 U.S.C. 106(g), 40113, 44701. 

Sec. 39.13 [Amended] 

2. The FAA amends Sec. 39.13 by adding the following new AD: