AD 2008-21-03

This AD is effective November 13, 2008.

The Director of the Federal Register approved the incorporation by reference of a certain publication listed in this AD as of November 13, 2008.

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

Allen Rauschendorfer, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone (425) 917-6432; fax (425) 917-6590.

We issued a notice of proposed rulemaking (NPRM) to amend 14 CFR Part 39 to include an airworthiness directive (AD) that would apply to all Boeing Model 737-300, -400, and -500 series airplanes. That NPRM was published in the Federal Register on March 26, 2008 (73 FR 15959). That NPRM proposed to require repetitive inspections for discrepancies of the fuse pins of the inboard and outboard midspar fittings of the nacelle strut, and corrective actions if necessary.

We gave the public the opportunity to participate in developing this AD. We considered the comments received.

Boeing supports the NPRM.

Deutsche Lufthansa (DLH) states that during inspections done per the AMM, for which the left- and right-hand pylons have to be removed, it observed several instances of corrosion or damaged chrome plating of the midspar fuse pins; the defective pins were replaced. Therefore, DLH supports the repetitive inspections of the fuse pins.

DLH asks that the initial inspection procedure done per Maintenance Planning Document (MPD) Item 54-322-01, of the applicable airplane maintenance manual (AMM), be acceptable for compliance with the initial inspection required by the NPRM. In addition, DLH does not support the compliance times for the initial inspection. DLH feels that the inspection of the fuse pins done during its maintenance check per the AMM provides the same level of safety as the initial inspection done per the service bulletin referenced in the NPRM.

We do not agree. The AMM only includes procedures for access and does not provide inspection procedures; therefore, the service bulletin provides the inspection procedures. If DLH believes that its inspection procedures provide an acceptable alternative, under the provisions of paragraph (g) of this AD, we will consider requests for approval of an alternative method of compliance if sufficient data are submitted to substantiate that the alternative inspection would provide an acceptable level of safety.

We reviewed the relevant data, considered the comments received, and determined that air safety and the public interest require adopting the AD as proposed.

We estimate that this AD will affect 616 airplanes of U.S. registry. We also estimate that it will take 4 work-hours per product to comply with the inspection in 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 $197,120, or $320 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.

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.

You can find our regulatory evaluation and the estimated costs of compliance in the AD Docket.

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: