Airworthiness Directives; McDonnell Douglas Model MD-11 and -11F Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-11 and -11F airplanes. This proposal would require revising the wire connection stackups for the terminal strip of the generator feeder tail compartment of the auxiliary power unit (APU), and removing a nameplate, as applicable. For certain airplanes, this proposal also would require replacing the terminal strips and revising the terminal hardware stackup for the feeder of the center cargo loading system. This action is necessary to prevent arcing damage to the terminal strips and damage to the adjacent structure, which could result in smoke and/or fire in the center and/or aft cargo compartments. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by September 8, 2003.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-161-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: 9-anm-nprmcomment@faa.gov. Comments sent via fax or the Internet must contain “Docket No. 2001-NM-161-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

The service information referenced in the proposed rule may be obtained from Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024). This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California.

FOR FURTHER INFORMATION CONTACT:

Brett Portwood, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone (562) 627-5350; fax (562) 627-5210.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received.

Submit comments using the following format:

• Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
• For each issue, state what specific change to the proposed AD is being requested.
• Include justification (e.g., reasons or data) for each request.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2001-NM-161-AD.” The postcard will be date stamped and returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-161-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

As part of its practice of re-examining all aspects of the service experience of a particular aircraft whenever an accident occurs, the FAA has become aware of an incident in which arcing occurred between the power feeder cables and support bracket of the terminal strips on a McDonnell Douglas Model MD-11 airplane. Investigation revealed that inadequate clearance exists between the terminal strips and associated support brackets in the center and aft cargo compartments. This condition, if not corrected, could result in arcing damage to the terminal strips and damage to the adjacent structure, which could result in smoke and/or fire in the center and/or aft cargo compartments.

The terminal strips and associated support brackets in the center and aft cargo compartments on certain McDonnell Douglas Model MD-11F airplanes are identical to those on the affected Model MD-11 airplanes. Therefore, both of these models may be subject to the same unsafe condition.

Other Related Rulemaking

The FAA, in conjunction with Boeing and operators of Model MD-11 and -11F airplanes, has reviewed all aspects of the service history of those airplanes to identify potential unsafe conditions and to take appropriate corrective actions. This proposed airworthiness directive (AD) is one of a series of corrective actions identified during that process. We have previously issued several other ADs and may consider further rulemaking actions to address the remaining identified unsafe conditions.

Explanation of Relevant Service Information

We have reviewed and approved McDonnell Douglas Alert Service Bulletin MD11-24A173, Revision 02, dated May 2, 2002, including Evaluation Form. The service bulletin describes procedures for revising the wire connection stackups for the terminal strip of the generator feeder tail compartment of the auxiliary power unit (APU), and removing a nameplate, as applicable. For certain airplanes, the service bulletin also describes procedures for replacing the terminal strips and revising the terminal hardware stackup for the feeder of the center cargo loading system. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

Explanation of Requirements of Proposed Rule

Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require accomplishment of the applicable actions specified in the service bulletin described previously, except as discussed below.

Differences Between Proposed AD and Service Bulletin

Operators should note that the service bulletin specifies to repair damaged structure per the Structural Repair Manual (SRM). However, the SRM does not provide procedures for repair of certain structural material. Therefore, this proposed AD would require the repair of damaged structure that is not covered in the SRM to be accomplished per a method approved by us.

Although the referenced service bulletin describes procedures for completion and submission of an inspection report and service bulletin evaluation, this proposed AD would not require those actions.

Changes to 14 CFR Part 39/Effect on the Proposed AD

On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's airworthiness directives system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance (AMOCs). Because we have now included this material in part 39, only the office authorized to approve AMOCs is identified in each individual AD.

Cost Impact

There are approximately 154 Model MD-11 and -11F airplanes of the affected design in the worldwide fleet. We estimate that 67 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately between 1 and 2 work hours per airplane (depending on the airplane configuration) to accomplish the proposed actions, and that the average labor rate is $65 per work hour. Required parts would cost approximately $102 per airplane. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to between $11,189 and $15,544, or between $167 and $232 per airplane (depending on the airplane configuration).

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed AD were not adopted. However, for affected airplanes within the period under the warranty agreement, we have been advised that the manufacturer has committed previously to its customers that it will bear the cost of replacement parts. We also have been advised that manufacturer warranty remedies are available for labor costs associated with accomplishing the actions required by this proposed AD. Therefore, the future economic cost impact of this AD may be less than the cost impact figure indicated above.

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.

Regulatory Impact

The regulations proposed herein would 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.

For the reasons discussed above, I certify that this proposed regulation (1) is not a “significant regulatory action” under Executive Order 12866; (2) is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Safety

The Proposed Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.