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 replacement of the existing terminal strips and supports above the main cabin area; and installation of spacers between terminal strips and mounting brackets in the avionics compartment; as applicable. This action would require replacing the applicable terminal strips in the avionics compartment with new terminal strips. This action also would require performing an inspection to detect arcing damage of the surrounding structure of the terminal strips and electrical cables in the avionics compartment, and repairing or replacing any damaged component with a new component. This proposal is prompted by reports of arcing between the power feeder cables and support brackets of the terminal strips on airplanes previously modified per the existing AD. The actions specified by the proposed AD are intended to prevent electrical arcing caused by power feeder cable terminal lugs grounding against terminal strip support brackets, which could result in smoke and fire in the main cabin or avionics compartment.

DATES:

Comments must be received by November 19, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-63-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-63-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 90712-4137; 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 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-63-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-63-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

On February 10, 2000, the FAA issued AD 2000-03-15, amendment 39-11574 (65 FR 8025, February 17, 2000), applicable to certain McDonnell Douglas Model MD-11 and -11F series airplanes, to require replacement of the existing terminal strips and supports above the main cabin area; and installation of spacers between terminal strips and mounting brackets in the avionics compartment; as applicable. That action was prompted by a report indicating that, during flight, an incident of electrical arcing occurred at a terminal strip located overhead in the main cabin. The requirements of that AD are intended to prevent electrical arcing caused by power feeder cable terminal lugs grounding against terminal strip support brackets, which could result in smoke and fire in the main cabin or avionics compartment.

Other Related Rulemaking

The FAA, in conjunction with Boeing and operators of Model MD-11 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.

Actions Since Issuance of Previous Rule

Since the issuance of AD 2000-03-15, the FAA has received a report of arcing between the power feeder cables and support brackets of the terminal strips on a McDonnell Douglas Model MD-11 series airplane. This airplane had been modified per the requirements of paragraph (b) of AD 2000-03-15 (which referenced McDonnell Douglas Alert Service Bulletin MD11-24A147, dated March 24, 1999, as the appropriate source of service information for accomplishing the modification). Investigation revealed that the design and installation did not provide adequate clearance between the terminal strips and support brackets, which allowed a power feeder cable terminal lug to ground against a terminal strip support bracket. This condition, if not corrected, could result in electrical arcing and consequent smoke and/or fire in the main cabin or avionics compartment.

The incident that prompted this proposed AD is not considered to be related to an accident that occurred off the coast of Nova Scotia involving a McDonnell Douglas Model MD-11 series airplane. The cause of that accident is still under investigation.

Explanation of Relevant Service Information

The FAA has reviewed and approved McDonnell Douglas Alert Service Bulletin MD11-24A178, dated May 14, 2001, which describes the following procedures:

1. Replacing the applicable terminal strips in the avionics compartment with new terminal strips (including inspecting wires for damage, repairing any damaged wire, and removing the nameplate); and

2. Performing a general visual inspection to detect arcing damage of the surrounding structure of the terminal strips and electrical cables in the avionics compartment, and repairing or replacing any damaged component with a new component.

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 supersede AD 2000-03-15 to continue to require replacing the existing terminal strips and supports above the main cabin at station Y=5-32.000 with new terminal strips and supports. The proposed AD also would require accomplishment of the actions specified in the service bulletin described previously, except as described below.

The modification required by paragraph (b) of AD 2000-03-15 would effectively be removed from the airplane when the replacement required by paragraph (b)(2) of this proposed AD is done.

Differences Between Proposed Rule 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 adequate 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 the FAA.

Cost Impact

There are approximately 133 Model MD-11 and -11F series airplanes listed in McDonnell Douglas Alert Service Bulletin MD11-24A178, dated May 14, 2001, of the affected design in the worldwide fleet. The FAA estimates that 52 airplanes of U.S. registry would be affected by this proposed AD.

The new actions that are proposed in this AD action would take approximately 3 (for Group 1 airplanes) and 4 (for Group 2 airplanes) work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts would cost approximately $1,142 per airplane. Based on these figures, the cost impact of the proposed requirements of this AD on U.S. operators is estimated to be $1,322 (for Group 1 airplanes) and $1,382 (for Group 2 airplanes) 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. 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. However, the FAA has 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 rule on U.S. operators may be less than the cost impact figure indicated above.

Currently, there are no Model MD-11 series airplanes listed in McDonnell Douglas Alert Service Bulletin MD11-24A150, dated March 25, 1999, on the U.S. Register. However, should an affected airplane be imported and placed on the U.S. Register in the future, it would require approximately 1 work hour to accomplish the replacement currently required by AD 2000-03-15, and retained in this proposed AD, at an average labor rate of $60 per work hour. The cost of required parts would be $885. Based on these figures, the cost impact of this AD for this replacement would be $945 per airplane.

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.