Airworthiness Directives; McDonnell Douglas Model MD-90-30 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 all McDonnell Douglas Model MD-90-30 airplanes. This proposal would require one-time inspections to detect discrepancies of electrical wiring installations in various areas of the airplane; and corrective actions, if necessary. This action is necessary to prevent electrical arcing and/or heat-damaged wiring due to improper wire installations or maintenance practices, which could result in fire and smoke in various areas of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by July 29, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-84-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-84-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:

Technical Information: George Mabuni, 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) 627-5341; fax (562) 627-5210.

Other Information: Judy Golder, Airworthiness Directive Technical Editor/Writer; telephone (425) 687-4241, fax (425) 227-1232. Questions or comments may also be sent via the Internet using the following address: judy.golder@faa.gov. Questions or comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 for Windows or ASCII text.

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-84-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-84-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has become aware of several instances of damaged wiring insulation and chafed wiring in various areas on McDonnell Douglas Model MD-90-30 airplanes. Investigation revealed that such damage and chafing may be due to improper wire installations or maintenance practices. This condition, if not corrected, could lead to electrical arcing and/or heat-damaged wiring, which could result in fire and smoke in various areas of the airplane.

Other Relevant Rulemaking

The FAA has previously issued AD 2000-11-01, amendment 39-11749 (65 FR 34321, May 26, 2000), applicable to certain McDonnell Douglas Model DC-9-81 (MD-81), DC-9-82 (MD-82), DC-9-83 (MD-83), DC-9-87 (MD-87), MD-88, and MD-90-30 airplanes. That AD requires determining whether, and at what locations, metallized polyethyleneteraphthalate (MPET) insulation blankets are installed, and replacing MPET insulation blankets with new insulation blankets. The FAA recommends that the actions that would be required by this proposed AD be accomplished after accomplishing the replacement required by AD 2000-11-01. This proposed AD would not affect the current requirements of that AD.

Explanation of Relevant Service Information

The FAA has reviewed and approved the following service bulletins:

• Boeing Service Bulletin MD90-24-066, including Appendix A, Revision 01, dated February 8, 2001, which describes procedures for a one-time visual inspection of all electrical wiring installations in the flight compartment and forward drop ceiling area.
• Boeing Service Bulletin MD90-24-067, including Appendix A, Revision 01, dated February 8, 2001, which describes procedures for a one-time visual inspection of all electrical wiring installations in the electronic/electrical (E/E) compartment.
• Boeing Service Bulletin MD90-24-068, including Appendix A, Revision 01, dated February 8, 2001, which describes procedures for a one-time visual inspection of all electrical wiring installations in the forward passenger compartment from stations Y=260.000 to Y=902.000.
• Boeing Service Bulletin MD90-24-069, including Appendix A, Revision 01, dated February 8, 2001, which describes procedures for a one-time visual inspection of all electrical wiring installations in the aft passenger compartment from stations Y=902.000 to Y=1395.000.
• Boeing Service Bulletin MD90-24-070, including Appendix A, Revision 01, dated February 8, 2001, which describes procedures for a one-time visual inspection of all electrical wiring installations in the forward and mid cargo compartments from stations Y=218.000 to Y=845.000.
• Boeing Service Bulletin MD90-24-071, including Appendix A, Revision 01, dated February 8, 2001, which describes procedures for a one-time visual inspection of all electrical wiring installations in the aft cargo compartment from stations Y=1064.000 to Y=1369.000.
• Boeing Service Bulletin MD90-24-072, including Appendix A, Revision 01, dated February 8, 2001, which describes procedures for a one-time visual inspection of all electrical wiring installations in the forward accessory compartment from stations Y=41.000 to Y=70.000.

All of these service bulletins also describe procedures for corrective actions that may be necessary. These include repairing cracked, split, or torn wiring insulation; re-attaching nylon (caterpillar) grommets; installing smaller-sized clamps; adjusting, replacing, or tightening sta-straps; repositioning certain wiring or clamps; tightening or securing clamps, terminals, or wire bundles; re-torquing screw terminals of the flag lug bus bar; repairing or replacing certain wiring, terminals, splices, or connectors; installing protective sleeving over wiring; and installing a silicone glass cloth over conduit ends. 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 require accomplishment of the actions specified in the service bulletins described previously, except as discussed below.

Differences Between Service Bulletins and Proposed AD

The service bulletins specify accomplishment of “visual” inspections. The FAA has determined that the inspections described in the service bulletins constitute “detailed inspections.” Therefore, this proposed AD would require accomplishment of detailed inspections. Note 3 of this proposed AD defines such inspections.

Also, Appendix A of each service bulletin contains a form to report inspection findings. This proposed AD would NOT require such reports to be submitted to the FAA.

Cost Impact

There are approximately 115 airplanes of the affected design in the worldwide fleet. The FAA estimates that 25 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 49 work hours per airplane to accomplish all of the proposed inspections, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the inspections proposed by this AD on U.S. operators is estimated to be $73,500, or $2,940 per airplane.

Warranty remedies may be available from the airplane manufacturer for labor costs associated with this proposed AD. As a result, the costs attributable to the proposed AD may be less than stated above.

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. 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.