AD 2005-17-04

Effective September 26, 2005.

The Director of the Federal Register approved the incorporation by reference of certain publications listed in the AD as of September 26, 2005.

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

Samuel Lee, Aerospace Engineer, Propulsion Branch, ANM-140L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone (562) 627-5262; fax (562) 627-5210.

You may 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 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 McDonnell Douglas airplanes. That NPRM was published in the Federal Register on March 22, 2005 (70 FR 14432). That NPRM proposed to require a general visual inspection for damage to the Firex discharge pipes and wye assembly of the fire extinguishing system of the number 2 engine; and corrective and other specified actions, as applicable.

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

Since we issued the NPRM, Boeing has released Boeing Alert Service Bulletin DC10-26A065, Revision 1, dated May 20, 2005; and Boeing Alert Service Bulletin MD11-26A060, Revision 1, dated May 10, 2005. We have reviewed the procedures in the revised service bulletins and determined that they are essentially the same as those in the original issues of the service bulletins, with no additional work required. The revised service bulletins show an increase in the cost for required parts. However, we have determined that this increase will not have a significant impact on the cost to operators. Therefore, we have revised paragraphs (c) and (f) in the final rule to specify the revised service bulletins as the primary sources of service information; and revised the “Costs of Compliance” section in the final rule to reflect the increased parts cost. We have also inserted new paragraph (g) in the final rule to give credit for modifications already accomplished using the original issues of the service bulletins and re-identified paragraph (g) of the NPRM as paragraph (h) in the final rule.

One commenter supports the intent of the subject NPRM and the proposed actions of the AD.

One commenter agrees with the intent of the NPRM but requests that we revise the compliance time from 12 months to 18 months. The commenter states that a compliance time of 12 months will force operators to perform required modifications during line maintenance between heavy maintenance check intervals. The commenter states that performing the modifications during heavy maintenance checks in a hangar environment, instead of during line operations, would reduce the chances of modification errors. The commenter states that it has not had any reports of problems with delivery of the Firex agent when the engine fire extinguishing system was activated and asserts that an additional six months added to the compliance time would have no significant impact on safety.

We agree with this request. We have re-evaluated all available reports and have determined that increasing the compliance time by six months will not have any significant impact on safety. Therefore, we have revised the compliance time to 18 months in the final rule.

We discovered a math error in the “Costs of Compliance” section of the NPRM. The total number of U.S.-registered airplanes in the “Inspection Costs” table is shown as 343; it should have been 453. Though changing the number of airplanes from 343 to 453 appears to increase costs for operators, we have determined that no additional burden is imposed on operators because 453 is the number of airplanes actually identified by the service information as referenced in the applicability of this AD. We have revised the “Inspection Costs” table in the final rule to reflect this correction.

We have carefully reviewed the available data, including the comments that have been 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 not significantly increase the economic burden on any operator and will not increase the scope of the AD.

There are about 530 airplanes of the affected design in the worldwide fleet. The following tables provide the estimated costs for U.S. operators to comply with this AD. The required actions will be performed at an estimated average labor rate of $65 per work hour.

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):