AD 2006-07-04

This AD becomes effective May 4, 2006.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of May 4, 2006.

You may examine the AD docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, Washington, DC.

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

Doug Pegors, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6504; fax (425) 917-6590.

You may examine the airworthiness directive (AD) docket on the Internet at http://dms.dot.gov or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the 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 January 24, 2005 (70 FR 3320). That NPRM proposed to require repetitive general visual inspections for dirt, debris, and drain blockage and cleaning of the aft fairing cavities of the engine struts; and modification of the aft fairings, which would terminate the repetitive general visual inspections.

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

Southwest Airlines and AirTran Airways support the NPRM.

Alaska Airlines requests that we revise the dimension between certain fastener holes specified in Figures 3, 4, 5, and 6 of Boeing Special Attention Service Bulletin 737-54-1041, dated January 22, 2004. Alaska Airlines states that the dimension between an existing fastener hole and the new fastener hole is called out in the ten-thousandths (1.6772 inches); any deviation from this exact measurement would require approval of an alternative method of compliance (AMOC). Alaska Airlines suggests dimensions of 1.67 or 1.68 inches with a standard tolerance of ±0.03 inch. If we cannot revise the dimension, the commenter instead requests that we clarify why such a tight tolerance would be required.

We agree with Alaska Airlines' request, since there is no technical justification for requiring such a tight tolerance between fastener holes. Since issuance of the NPRM, Boeing has published Service Bulletin 737-54-1041, Revision 1, dated December 1, 2005. The procedures in Revision 1 of the service bulletin are essentially the same as those in the original issue, dated January 22, 2004, which we referenced in the NPRM as the appropriate source of service information. Revision 1 allows a dimension of 1.647 inches to 1.707 inches between fastener holes. Therefore, we have revised this AD to also allow use of Revision 1 for accomplishing the actions specified in this AD. We have also revised paragraph (c) of this AD to reference Revision 1. Since the effectivity of Revision 1 is the same as the effectivity of the original issue, the applicability of this AD has not changed.

We have revised this action to clarify the appropriate procedure for notifying the principal inspector before using any approved AMOC on any airplane to which the AMOC applies.

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.

This AD affects about 1,406 airplanes worldwide and about 549 U.S.-registered airplanes. 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):