AD 2007-23-10

This AD becomes effective December 20, 2007.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in the AD as of December 20, 2007.

For service information identified in this AD, contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207.

Binh Tran, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6485; fax (425) 917-6590.

You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Operations office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Operations office (telephone (800) 647-5527) is located on the ground floor of the West Building at the DOT street address stated in the ADDRESSES section.

The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 CFR part 39 to include an AD that would apply to certain Boeing Model 737-600, -700, -700C, -800 and -900 series airplanes. That NPRM was published in the Federal Register on March 30, 2007 (72 FR 15073). That NPRM proposed to require an inspection of the fillet sealant at the inboard and outboard sides of the receptacles in the wheel wells of the main landing gear, and related investigative/corrective actions if necessary.

We provided the public the opportunity to participate in the development of this AD. We have considered the comments received.

Boeing and AirTran Airways support the NPRM's proposed actions.

AirTran Airways requests that the expected parts usage and parts availability be reviewed and addressed for feasibility prior to the release of the final rule to ensure that parts shortages will not necessitate requests for unnecessary alternative means of compliance or adjustments of the compliance time. The commenter adds that there are 36 part numbers that could possibly need replacement if there is corrosion beyond the acceptable limits in the service bulletin. Of these 36 connectors, 9 part numbers are not available; of those, 5 do not appear to be in the production pipeline. Quite a few part numbers show less than a dozen available.

We agree with the request and have coordinated with Boeing regarding AirTran's concern. The NPRM cited Boeing Special Attention Service Bulletin 737-24-1169, dated December 15, 2006. Since we issued the NPRM, Boeing has revised the service bulletin. Revision 1, dated August 6, 2007, provides optional connector part numbers, which will ensure adequate replacement parts for the specified corrective actions. The remaining information in Revision 1 is essentially unchanged. We have revised paragraphs (c) and (f) of this final rule to refer to Revision 1 of the service bulletin as the appropriate source of service information for the applicability and the required actions. We have included credit for actions previously performed in accordance with the original service bulletin.

We have carefully reviewed the available data, including the comments received, and determined that air safety and the public interest require adopting the AD with the changes described previously. We have determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD.

There are about 333 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this AD.

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 regulatory evaluation of the estimated costs to comply with this AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

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 Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):