AD 2005-07-03

This AD becomes effective May 4, 2005.

The incorporation by reference of a certain publication listed in the AD is approved by the Director of the Federal Register as of May 4, 2005.

For service information identified in this AD, contact Boeing Commercial Airplanes, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024).

Docket: The AD docket contains the proposed AD, comments, and any final disposition. You can examine the 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 U.S. Department of Transportation, 400 Seventh Street SW, room PL-401, Washington, DC. This docket number is FAA-2004-18774; the directorate identifier for this docket is 2003-NM-212-AD.

Wahib Mina, Aerospace Engineer, Airframe Branch, ANM-120L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5324; fax (562) 627-5210.

The FAA proposed to amend 14 CFR Part 39 with an AD for certain McDonnell Douglas Model DC-9-10, -20, -30, -40, and -50 series airplanes; and Model DC-9-81 (MD-81) and DC-9-82 (MD-82) airplanes. That action, published in the Federal Register on August 5, 2004 (69 FR 47388), proposed to require repetitive detailed inspections of the upper and lower caps of the rear spar of the left and right wings, and corrective action if necessary. That action also proposed to provide an optional modification that would end the repetitive inspections.

We provided the public the opportunity to participate in the development of this AD. We have considered the comments that have been submitted on the proposed AD.

One commenter requests that we revise the corrective action specified in the proposed AD. The commenter states there is a significant discrepancy between the proposed AD and McDonnell Douglas DC-9 Service Bulletin 57-179, Revision 1, dated December 21, 1994 (referenced as the appropriate source of service information for accomplishing the proposed actions). The commenter notes that the proposed AD will require that if a crack is found on either the upper or lower spar cap, then both the upper and lower spar caps must be either permanently repaired as specified in paragraph (j) of the proposed AD or temporarily repaired as specified in paragraph (k) of the proposed AD. The commenter contends that the intent of the service bulletin is to repair (permanently or temporarily) only the cracked spar caps and then repetitive inspections can continue on spar caps that are not cracked. The commenter provides data that it contends strongly indicate that repair of both spar caps is not necessary if only one of the spar caps is found to be cracked. The commenter also refers to AD 88-01-04, which does not require repair of both spar caps if only one is found to be cracked.

The commenter states that requiring both spar caps to be repaired if either spar cap is found cracked would appear to be a requirement to retrofit all airplanes that have repaired only a single spar cap and therefore may result in grounded airplanes. The commenter also states that repairing both spar caps if only one spar cap is cracked would impose a large and unnecessary burden on operators.

The commenter requests that the final rule require only temporary or permanent repair of the cracked spar cap and continuing inspections of the uncracked spar cap on that spar.

We agree with the commenter to revise the final rule. When only one spar cap is found to be cracked on one spar, the intent of the service bulletin is to repair the cracked spar cap and continue inspections of the uncracked spar cap on that spar. We have revised paragraphs (j) and (k) of the final rule accordingly.

The same commenter requests that we revise the Cost of Compliance section of the proposed AD. The commenter notes that the proposed AD estimates the cost at $260 per airplane, per inspection. The commenter states that based on its experience, the average cost to perform the inspections is $610 per airplane.

We do not agree to revise the Costs of Compliance section of the final rule. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as the time required to gain access and close up, planning time, or time necessitated by other administrative actions. Thus, the cost estimate in the final rule is only for the cost of the inspection. In addition, the cost estimate is based on the manufacturer's data provided in the service bulletin. We have not changed the final rule in this regard.

We have carefully reviewed the available data, including the comments that have been submitted, 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.

We have revised the wording in paragraph (n) of the final rule to clarify that for the applicable airplanes the actions specified in paragraph (n) are required only if the actions specified in paragraph (m) are being accomplished.

There are about 1,163 airplanes worldwide of the affected design. This AD will affect about 583 airplanes of U.S. registry. The inspection will take about 4 work hours per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the AD for U.S. operators is $151,580, or $260 per airplane, per inspection cycle.

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. See the ADDRESSES section for a location to examine the regulatoory 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 FAA amends § 39.13 by adding the following new airworthiness directive (AD):