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

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-11 and MD-11F series airplanes, that currently requires modification of the external power feeder cable clamping installation. That AD was prompted by reports of damage to the external power feeder cables located under the forward cargo compartment floor, which was caused by excessive cable length and/or maintenance personnel stepping on the cables. This action would add a new requirement to accomplish a detailed visual inspection of the external power feeder cables to detect chafed or damaged wires; and repair, if necessary. The actions specified by the proposed AD are intended to prevent arcing from occurring under the forward cargo compartment floor as a result of damaged external power feeder cables, a situation that could lead to a fire at this location.

DATES:

Comments must be received by March 17, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-265-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays.

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: Technical Publications Business Administration, Dept. C1-L51 (2-60). This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, 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, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; 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 notice may be changed in light of the comments received.

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 notice must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 99-NM-265-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. 99-NM-265-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On May 23, 1994, the FAA issued AD 94-11-06, amendment 39-8922 (59 FR 27972, May 31, 1994), which is applicable to certain McDonnell Douglas Model MD-11 and MD-11F series airplanes. That AD requires modification of the external power feeder cable clamping installation. The requirements of that AD are intended to prevent arcing from occurring under the forward cargo compartment floor as a result of damaged external power feeder cables, a situation that could lead to a fire at this location.

Actions Since Issuance of Previous Rule

Since the issuance of AD 94-11-06, the FAA has reviewed and approved McDonnell Douglas Alert Service Bulletin MD11-24A078, Revision 01, dated June 16, 1999, which describes procedures for a detailed visual inspection of the external power feeder cables to detect chafed or damaged wires; and repair, if necessary. The service bulletin also describes procedures for the same modification of the external power feeder cable clamping installation that is described in McDonnell Douglas Service Bulletin 24-78, dated May 10, 1994 (which was referenced in AD 94-11-06 as the appropriate source of service information).

Accomplishment of the actions specified in the service bulletins 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 supersede AD 94-11-06 to continue to require modification of the external power feeder cable clamping installation. The proposed AD also would require accomplishment of the actions specified in McDonnell Douglas Alert Service Bulletin MD11-24A078 described previously.

Other Related Rulemaking

The FAA, in conjunction with Boeing and operators of Model MD-11 and MD-11F series airplanes, is continuing to review all aspects of the service history of those airplanes to identify potential unsafe conditions and to take appropriate corrective actions. This proposed AD is one of a series of actions identified during that process. The process is continuing and the FAA may consider additional rulemaking actions as further results of the review become available.

Cost Impact

There are approximately 110 airplanes of the affected design in the worldwide fleet. The FAA estimates that 46 airplanes of U.S. registry would be affected by this proposed AD.

The modification of the external power feeder cable clamping installation that is currently required by AD 94-11-06, and retained in this proposed AD, takes approximately 3 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts cost approximately $395 per airplane. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $26,450, or $575 per airplane.

The new actions that are proposed in this AD action would take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the new proposed requirements of this AD on U.S. operators is estimated to be $2,760, or $60 per airplane.

The cost impact figures discussed above are based on assumptions that no operator has yet accomplished any of the current or proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

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.