04-4927. Airworthiness Directives; McDonnell Douglas Model DC-10-30 Airplane

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD), applicable to a certain McDonnell Douglas Model DC-10-30 airplane. The proposal would require an inspection of the power feeder cable assembly of the auxiliary power unit (APU) for chafing, correct type of clamps, and proper clamp installation; and corrective actions, if necessary. This action is necessary to prevent the loss of the APU generator due to chafing of the generator power feeder cables, and consequent electrical arcing and smoke/fire in the APU compartment. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by April 19, 2004.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-237-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 [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-237-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 Airplanes, 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:

Natalie Phan-Tran, Aerospace Engineer, Systems and Equipment Branch, ANM-130L, FAA, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712-4137; telephone [phone]; fax [phone].

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 2002-NM-237-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. 2002-NM-237-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Background

In July 1996, a Boeing Model 747 series airplane was involved in an accident. As part of re-examining all aspects of the service experience of the airplane involved in the accident, the FAA participated in design review and testing to determine possible sources of ignition in center fuel tanks. As part of the review, we examined fuel system wiring with regard to the possible effects that wire degradation may have on arc propagation.

In 1997 in a parallel preceding, at the recommendation of the White House Commission on Aviation Safety and Security, the FAA expanded its Aging Transport Program to include non-structural systems and assembled a team for evaluating these systems. This team performed visual inspections of certain transport category airplanes for which 20 years or more had passed since date of manufacture. In addition, the team gathered information from interviews with FAA Principal Maintenance Inspectors and meetings with representatives of airplane manufacturers. This evaluation revealed that the length of time in service is not the only cause of wire degradation; inadequate maintenance, contamination, improper repair, and mechanical damage are all contributing factors. From the compilation of this comprehensive information, we developed the Aging Transport Non-Structural Systems Plan to increase airplane safety by increasing knowledge of how non-structural systems degrade and how causes of degradation can be reduced.

In 1998, an accident occurred off the coast of Nova Scotia involving a McDonnell Douglas Model MD-11 series airplane. Investigation indicates that a fire broke out in the cockpit and first class overhead area. Although the ignition source of the fire has not been determined, the FAA, in conjunction with Boeing and operators of Model MD-11, DC-8, DC-9, DC-10, and DC-9-80 series airplanes, is reviewing all aspects of the service history of those airplanes to identify potential unsafe conditions associated with wire degradation due to various contributing factors (e.g., inadequate maintenance, contamination, improper repair, and mechanical damage) and to take appropriate corrective actions. This proposed airworthiness directive (AD) is one of a series of corrective actions identified during that process.

In 1999, the FAA Administrator established a formal advisory committee to facilitate the implementation of the Aging Transport Non-Structural Systems Plan. This committee, the Aging Transport Systems Rulemaking Advisory Committee (ATSRAC), is made up of representatives of airplane manufacturers, operators, user groups, aerospace and industry associations, and government agencies. As part of its mandate, ATSRAC will recommend rulemaking to increase transport category airplane safety in cases where solutions to safety problems connected to aging systems have been found and must be applied. Detailed analyses of certain transport category airplanes that have been removed from service, studies of service bulletins pertaining to certain wiring systems, and reviews of previously issued ADs requiring repetitive inspections of certain wiring systems, have resulted in valuable information on the cause and prevention of wire degradation due to various contributing factors (e.g., inadequate maintenance, contamination, improper repair, and mechanical damage).

In summary, as a result of the investigations described above, the FAA has determined that corrective action may be necessary to minimize the potential hazards associated with wire degradation and related causal factors (e.g., inadequate maintenance, contamination, improper repair, and mechanical damage).

Identification of Unsafe Condition

The FAA has received a report of a generator power feeder cable of the auxiliary power unit (APU) chafing and shorting against adjacent structure on a McDonnell Douglas Model DC-10 airplane. Investigation revealed the cause of such chafing and arcing to be installation of an incorrect cable clamp and improperly positioned clamp during manufacturing. These conditions, if not corrected, could result in loss of the APU generator due to chafing of the generator power feeder cables and consequent electrical arcing and smoke/fire in the APU compartment.

Similar Airplanes

The power feeder cable assemblies of the APUs on certain McDonnell Douglas Model MD-10-10F airplanes are identical to those on the affected Model DC-10 airplane. Therefore, all of these models may be subject to the same unsafe condition.

AD 2001-24-22, Amendment 39-12539

On November 28, 2001, the FAA issued AD 2001-24-22, amendment 39-12539 (66 FR 64119, December 12, 2001), applicable to certain McDonnell Douglas Model DC-10-10, -10F, -30, -30F (KC-10A and KDC-10), -40, and -40F airplanes; and Model MD-10-10F airplanes, to require an inspection of the power feeder cable assembly of the auxiliary power unit (APU) for chafing, correct type of clamps, and proper clamp installation; and corrective actions, if necessary. The requirements of that AD are intended to prevent loss of the APU generator due to chafing of the generator power feeder cables, and consequent electrical arcing and smoke/fire in the APU compartment. That action was intended to address the identified unsafe condition.

Actions Since Issuance of Previous Rule

Since issuance of that AD, the FAA was advised that one Model DC-10-30 airplane (fuselage number 0106) was excluded inadvertently from the effectivity of Section 1.A. of Boeing Alert Service Bulletin DC10-24A137, Revision 01, dated May 31, 2001, which is referenced in the applicability of AD 2001-24-22 as the appropriate source for determining the affected airplane fuselage numbers. Therefore, the additional airplane is also subject to the same unsafe condition addressed in AD 2001-24-22.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin DC10-24A137, Revision 02, dated October 15, 2001, which describes procedures that are essentially the same as those procedures included in Boeing Alert Service Bulletin DC10-24A137, Revision 01, dated May 31, 2001. This revision also adds an additional airplane fuselage number to the effectivity. No more work is necessary on airplanes changed as shown in Revision 01 of the service bulletin. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

Accomplishment of the actions specified in AD 2001-24-22 is acceptable for compliance with the requirements of this proposed AD.

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 bulletin described previously.

Since this proposed AD would expand the applicability of AD 2001-24-22, the FAA has considered a number of factors in determining whether to issue a new AD or to supersede the existing AD. The FAA has considered the entire fleet size that would be affected by superseding AD 2001-24-22 and the consequent workload associated with revising maintenance record entries. In light of this, the FAA has determined that a less burdensome approach is to issue a separate AD applicable only to the additional airplane. This proposed AD would not supersede AD 2001-24-22; airplanes listed in the applicability of AD 2001-24-22 are required to continue to comply with the requirements of that AD. This proposed AD is a separate AD action, and is applicable to only one McDonnell Douglas Model DC-10-30 airplane (fuselage number 0106), certificated in any category.

Cost Impact

The FAA estimates that 1 Model DC-10-30 airplane, having fuselage number 0106, of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hour per airplane to accomplish the proposed inspection, and that the average labor rate is $65 per work hour. Based on these figures, the cost impact of the proposed inspection on U.S. operators is estimated to be $65.

The cost impact figure discussed above is 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.

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.

§ 39.13

[Amended]

2. Section 39.13 is amended by adding the following new airworthiness directive:

McDonnell Douglas: Docket 2002-NM-237-AD.

Applicability: Model DC-10-30 airplane, fuselage number 0106; certificated in any category.

Compliance: Required as indicated, unless accomplished previously.

To prevent the loss of the auxiliary power unit (APU) generator due to chafing of the generator power feeder cables, and consequent electrical arcing and smoke/fire in the APU compartment, accomplish the following:

Inspection and Corrective Action(s), if Necessary

(a) Within 12 months after the effective date of this AD, do a general visual inspection of the power feeder cable assembly of the APU for chafing, correct type (including part number) of clamps, and proper clamp installation, per Boeing Alert Service Bulletin DC10-24A137, Revision 02, dated October 15, 2001.

Note 1:

For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or droplight and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

(1) Condition 1. If no signs of wire chafing are found, and all clamps are of the correct type (including the correct part number) and are installed properly, no further action is required by this AD.

(2) Condition 2. If any wire chafing, incorrect type of any clamp (including incorrect part number), or improper clamp installation is found, before further flight, do the applicable corrective action(s) (e.g., repair, replace, and modify discrepant part) per the Accomplishment Instructions of the service bulletin.

Actions Accomplished Per Previous Issues of Service Bulletin

(b) Accomplishment of the inspection and any applicable corrective actions, per Boeing Service Bulletin DC10-24-137, dated September 15, 1987, or Boeing Alert Service Bulletin DC10-24A137, Revision 01, dated May 31, 2001, before the effective date of this AD, is considered acceptable for compliance with the requirements of this AD.

Accomplishment of the Actions per AD 2001-24-22

(c) Accomplishment of the actions specified in AD 2001-24-22, amendment 39-12539, is acceptable for compliance with the requirements of this AD.

Alternative Methods of Compliance

(d) In accordance with 14 CFR 39.19, the Manager, Los Angeles Aircraft Certification Office, FAA, is authorized to approve alternative methods of compliance for this AD.

Issued in Renton, Washington, on February 25, 2004.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.