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: 

Bombardier Aerospace has completed a system safety review of the aircraft fuel system against fuel tank safety standards introduced in Chapter 525 of the Airworthiness Manual through Notice of Proposed Amendment (NPA) 2002-043. The identified non-compliances were then assessed using Transport Canada Policy Letter No. 525-001, to determine if mandatory corrective action is required. 

The assessment showed that it is necessary to introduce Critical Design Configuration Control Limitations (CDCCL), in order to preserve critical fuel tank system ignition source prevention features during configuration changes such as modifications and repairs, or during maintenance actions. Failure to preserve critical fuel tank system ignition source prevention features could result in a fuel tank explosion. * * * 

We are issuing this AD to require actions to correct the unsafe condition on these products. 

DATES: This AD becomes effective June 6, 2008. 

The Director of the Federal Register approved the incorporation by reference of certain publications listed in this AD as of June 6, 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: Richard Fiesel, Aerospace Engineer, Airframe and Propulsion Branch, ANE-171, FAA, New York Aircraft Certification Office, 1600 Stewart Avenue, Suite 410, Westbury, New York 11590; telephone (516) 228-7304; fax (516) 794-5531. 

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 March 11, 2008 (73 FR 12907). That NPRM proposed to correct an unsafe condition for the specified products. The MCAI states: 

Bombardier Aerospace has completed a system safety review of the aircraft fuel system against fuel tank safety standards introduced in Chapter 525 of the Airworthiness Manual through Notice of Proposed Amendment (NPA) 2002-043. The identified non-compliances were then assessed using Transport Canada Policy Letter No. 525-001, to determine if mandatory corrective action is required. 

The assessment showed that it is necessary to introduce Critical Design Configuration Control Limitations (CDCCL), in order to preserve critical fuel tank system ignition source prevention features during configuration changes such as modifications and repairs, or during maintenance actions. Failure to preserve critical fuel tank system ignition source prevention features could result in a fuel tank explosion. Revisions have been made to Part 2 "Airworthiness Limitations Items" of the Maintenance Requirements Manual of the affected models to introduce the required CDCCL. 

The corrective action is revising the Airworthiness Limitations Section of the Instructions for Continued Airworthiness to include the CDCCL data. 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 45 products of U.S. registry. We also estimate that it will take about 1 work-hour per product to comply with the basic requirements of this AD. The average labor rate is $80 per work-hour. Based on these figures, we estimate the cost of this AD to the U.S. operators to be $3,600, or $80 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: