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Proposed Rule

Airworthiness Directives; McDonnell Douglas Model DC-10-10, -15, -30, -30F, and -40 Series Airplanes, and KC-10A (Military) Airplanes

Document Details

Information about this document as published in the Federal Register.

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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 DC-10-10, -15, -30, -30F, and -40 series airplanes, and KC-10A (military) airplanes. This proposal would require a one-time inspection of the wiring and wire bundles of the aft main avionics rack (MAR) to determine if the wires are damaged, or riding or chafing on structure, clamps, braces, standoffs, or clips, and to detect damaged or out of alignment rubber cushions inserts of the wiring clamps; and corrective actions, if necessary. This proposal is prompted by an incident in which the automatic and manual cargo door test in the cockpit was inoperative during dispatch of the airplane, due to wiring of the main avionics rack chafing against clamps as a result of the wire bundles being installed improperly during production of the airplane. The actions specified by the proposed AD are intended to ensure that the wires that route from the main wire bundles to the MAR and associated brackets, clamps, braces, standoffs, and clips are installed properly. Improper installation of such wiring and structure could cause chafing of the wires/wire bundles, which could result in electrical arcing, smoke, and possible fire in the MAR.

DATES:

Comments must be received by March 13, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-211-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.

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FOR FURTHER INFORMATION CONTACT:

Natalie Phan-Tran, 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) 627-5343; fax (562) 627-5210.

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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-211-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-211-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 the automatic and manual cargo door test in the cockpit was inoperative. This incident occurred on a McDonnell Douglas Model MD-11 series airplane during dispatch.

Investigation revealed the insulation of a wire located on the aft main avionics rack (MAR) was worn through, and that the wire shorted to a coax clamp. The wires that route from the main wire bundles to the MAR also were found contacting clamps at other locations of the MAR. The cause of such chafing has been attributed to improper Start Printed Page 4191installation of the wire bundles in the MAR during production of the airplane.

Improper installation of the wires that route from the main wire bundles to the MAR or improper installation of the associated brackets, clamps, braces, standoffs, or clips could cause chafing of the wires/wire bundles, which could result in electrical arcing, smoke, and possible fire in the MAR.

The subject MAR on Model DC-10 series airplanes are similar to those on the affected McDonnell Douglas Model MD-11 series airplanes. Therefore, both of these airplanes may be subject to the same unsafe condition.

Other Related Rulemaking

The FAA, in conjunction with Boeing and operators of Model DC-10 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.

On April 13, 1999, the FAA issued AD 99-09-03, amendment 39-11135 (64 FR 19689, April 22, 1999), applicable to certain McDonnell Douglas MD-11 series airplanes, to require one-time inspection of the wiring and wire bundles of the aft MAR to determine if the wires are damaged, or riding or chafing on structure, clamps, braces, standoffs, or clips, and to detect damaged or out of alignment rubber cushion inserts of the wiring clamps; and corrective actions, if necessary. However, this proposed AD would not affect the current requirements of that previously issued AD.

Explanation of Relevant Service Information

The FAA has reviewed and approved McDonnell Douglas Alert Service Bulletin DC10-24A165, dated April 14, 1999, which describes procedures for a one-time general visual inspection to determine if the wires are damaged, or riding or chafing on structure, clamps, braces, standoffs, or clips, and to detect damaged or out of alignment rubber cushion inserts of the wiring clamps; and corrective actions, if necessary. The corrective actions include repairing damaged wiring; routing and tying all wires/wire bundles so that they are not in contact with adjacent wire bundles, clamps, or structure; installing silicone rubber coated glass cloth wrapping on wiring; and a general visual inspection of all brackets, clamps, braces, standoffs, and clips to make sure they are not bent or twisted and come in contact with wires/wire bundles. Accomplishment of the actions specified in the alert 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 actions specified in the alert service bulletin described previously, except as discussed below.

Differences Between the Proposed AD and the Referenced Alert Service Bulletin

The alert service bulletin specifies the following corrective actions for certain conditions: realigning the rubber cushion and replacing the clamp. However, the alert service bulletin does not provide any instructions for accomplishment of those procedures or reference other service information. The FAA has verified with the manufacturer that the appropriate source of service information for accomplishment of those procedures is McDonnell Douglas Process Engineering Order DPS 1.834-7, Revision CF, dated June 29, 1999. Therefore, this AD requires that those actions be accomplished in accordance with the process engineering order.

Cost Impact

There are approximately 412 airplanes of the affected design in the worldwide fleet. The FAA estimates that 300 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 3 work hours per airplane to accomplish the proposed inspection of the wiring and wire bundles, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of this inspection proposed by this AD on U.S. operators is estimated to be $54,000, or $180 per airplane.

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 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 ADDRESSESS.

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List of Subjects in 14 CFR Part 39

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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:

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PART 39—AIRWORTHINESS DIRECTIVES

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

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

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[Amended]

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

McDonnell Douglas: Docket 99-NM-211-AD.

Applicability: Model DC-10-10, -15, -30, -30F, and -40 series airplanes and KC-10A (military) airplanes, as listed in McDonnell Douglas Alert Service Bulletin DC10-24A165, dated April 14, 1999; certificated in any category.

Note 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (g) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously. Start Printed Page 4192

To ensure that the wires that route from the main wire bundles to the main avionics rack (MAR) and associated brackets, clamps, braces, standoffs, and clips are installed properly, accomplish the following:

One-Time General Visual Inspection

(a) Within 60 days after the effective date of this AD, perform a one-time general visual inspection of the wiring and wire bundles of the aft MAR to determine if the wires are damaged, or riding or chafing on structure, clamps, braces, standoffs, or clips, and to detect damaged or out of alignment rubber cushion inserts of the wiring clamps; in accordance with McDonnell Douglas Alert Service Bulletin DC10-24A165, dated April 14, 1999.

Note 2:

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 under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, 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.”

Note 3:

Where there are differences between this AD and the referenced alert service bulletin, the AD prevails.

Note 4:

The wording “main avionics rack” in this AD and the wording “main radio rack” in the alert service are used interchangeably.

Corrective Actions

(b) If any damaged wring is detected during the inspection required by paragraph (a) of this AD, prior to further flight, repair in accordance with the alert service bulletin.

(c) If any wire/wire bundle is detected to be riding or chafing on the subject areas during the inspection required by paragraph (a) of this AD, prior to further flight, accomplish paragraphs (c)(1), (c)(2), and (c)(3) of this AD.

(1) Route and tie all wires/wire bundles so they are not in contact with adjacent wire bundles, clamps or structure, and install silicon rubber coated glass cloth wrapping on wiring, if necessary, in accordance with the alert service bulletin.

(2) Perform a general visual inspection of all brackets, clamps, braces, standoffs, and clips to make sure they are not bent or twisted and do not come in contact with wires/wire bundles, in accordance with the alert service bulletin. If any of these parts is bent or twisted or is in contact with wires/wire bundles, prior to further flight, reposition in accordance with the alert service bulletin.

(3) Perform a general visual inspection of the clamps for proper alignment or for damage of the rubber cushion, in accordance with the alert service bulletin. If any clamp is not aligned properly, prior to further flight, realign the clamp in accordance with the alert service bulletin. If any rubber cushion is damaged, prior to further flight, replace the clamp in accordance with the alert service bulletin.

(d) If any damaged rubber cushion insert is detected during the inspection required by paragraph (a) of this AD, prior to further flight, replace the clamp with a new or serviceable clamp in accordance with McDonnell Douglas Process Engineering Order DPS 1.834-7, Revision CF, dated June 29, 1999.

(e) If any rubber cushion insert is out of alignment, prior to further flight, visually realign the cushion.

Reporting Requirement

(f) Within 10 days after accomplishing the inspection required by paragraph (a) of this AD, submit a report of the inspection results (both positive and negative findings) to the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate, 3960 Paramount Boulevard, Lakewood, California 90712-4137; fax (562) 627-5210. Information collection requirements contained in this regulation have been approved by the Office of Management and Budget (OMB) under the provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 2120-0056.

Alternative Methods of Compliance

(g) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Los Angeles ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Los Angeles ACO.

Note 5:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO.

Special Flight Permits

(h) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

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Issued in Renton, Washington, on January 20, 2000.

Donald L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

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[FR Doc. 00-1773 Filed 1-25-00; 8:45 am]

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