# AD 99-09-51: Airworthiness Directives; McDonnell Douglas Model MD-11 Series Airplanes

- Type: Airworthiness directive
- Effective: May 5, 1999
- Published: April 30, 1999, 64 FR 23179–23183
- Issued as: Final rule; request for comments
- Superseded by: Nothing supersedes this AD
- Amendment: 39-11154
- Docket: 99-NM-100-AD
- Official PDF: https://openairdocs.org/files/sha256/e8/61/e861388b0199b31639fd8a34bf26bffae96be59bf608fd166fd3eff47b2525a3 (from https://www.govinfo.gov/content/pkg/FR-1999-04-30/pdf/99-10815.pdf)
- Federal Register: https://www.federalregister.gov/documents/1999/04/30/99-10815/airworthiness-directives-mcdonnell-douglas-model-md-11-series-airplanes
- Page: https://openairdocs.org/ad/99-09-51

## Summary

This document publishes in the Federal Register an amendment adopting airworthiness directive (AD) 99-09-51 that was sent previously to all known U.S. owners and operators of certain McDonnell Douglas Model MD-11 series airplanes by individual notices. This AD requires visual inspections under the floorboards in the lower center cargo compartment at frame 1681 to verify that a certain bracket and a certain open face nylon clamp are installed to a specific support wire bundle and to detect damage of the subject wire bundle; repair of damaged wiring; and installation of certain silicone rubber coated with a glass cloth protective wrap around the wire bundle, if necessary. This action is prompted by an incident in which the insulation blanket between frames 1661 and 1681 in the lower center cargo compartment was found to be burnt due to a missing wiring harness support bracket/clamp on the wire bundle at frame 1681. The actions specified by this AD are intended to ensure that such a wire harness support bracket/clamp is installed; a missing bracket/clamp could cause the wire bundle to chafe against the frame, which could result in sparks, smoke, and possible fire in the lower center cargo compartment.

## The airworthiness directive

### 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.

### Sec. 39.13 [Amended]

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

99-09-51 McDonnell Douglas: Amendment 39-11154. Docket 99-NM-100-AD.

Applicability: Model MD-11 series airplanes, certificated in any category; having the following fuselage/factory serial numbers:

------------------------------------------------------------------------ Fuselage No. Serial No. ------------------------------------------------------------------------ 447........................................................ 48401 448........................................................ 48402 449........................................................ 48458 453........................................................ 48411 454........................................................ 48412 455........................................................ 48449 456........................................................ 48407 457........................................................ 48408 461........................................................ 48495 466........................................................ 48416 467........................................................ 48417 470........................................................ 48459 475........................................................ 48461 476........................................................ 48434 478........................................................ 48435 479........................................................ 48450 484........................................................ 48484 486........................................................ 48499 488........................................................ 48413 491........................................................ 48414 492........................................................ 48489 493........................................................ 48500 495........................................................ 48410 496........................................................ 48496 497........................................................ 48460 501........................................................ 48418 502........................................................ 48485 505........................................................ 48451 506........................................................ 48437 509........................................................ 48486 512........................................................ 48497 515........................................................ 48514 516........................................................ 48523 517........................................................ 48547 518........................................................ 48468 519........................................................ 48469 520........................................................ 48502 521........................................................ 48548 523........................................................ 48404 524........................................................ 48405 525........................................................ 48518 528........................................................ 48503 529........................................................ 48512 533........................................................ 48538 539........................................................ 48519 541........................................................ 48520 450........................................................ 48419 451........................................................ 48420 452........................................................ 48421 462........................................................ 48505 469........................................................ 48487 480........................................................ 48472 481........................................................ 48473 482........................................................ 48481 483........................................................ 48436 485........................................................ 48474 489........................................................ 48475 499........................................................ 48490 503........................................................ 48491 504........................................................ 58527 507........................................................ 48528 510........................................................ 48476 511........................................................ 48477 513........................................................ 48501 514........................................................ 48478 522........................................................ 48498 526........................................................ 48550 527........................................................ 48551 530........................................................ 48552 531........................................................ 48553 535........................................................ 48554 536........................................................ 48479 537........................................................ 48596 538........................................................ 48480 540........................................................ 48597 550........................................................ 48598 ------------------------------------------------------------------------

Note 1: This AD only affects Model MD-11 series airplanes equipped with a 72-inch cargo door. Model MD-11 series airplanes equipped with a 104-inch cargo door are not subject to the unsafe condition addressed by this AD due to the configuration of the wire bundles.

Note 2: 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 (c) 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.

To ensure that a wire harness support bracket/clamp is installed on the wire bundle at frame 1681, accomplish the following:

### (a)

  (a) Within 5 days after the effective date of this AD: Perform a one-time visual inspection under the floorboards in the lower center cargo compartment at frame 1681 (approximately one inch outboard of longeron R46) to verify that a bracket having part number P/N 9D0062-3-16-24 (or equivalent), and an open face nylon clamp having P/N NMC1001-1 or 383-1 (see Figure 1, Item 14/267), are installed to support wire bundle No. AGS9110. (The nylon clamp specified in this paragraph may be a larger size, depending on the size of the wire bundle.)

  (1) If the bracket and clamp are installed: Prior to further flight, perform a visual inspection to detect damage of the subject wire bundle. If any damage is detected, prior to further flight, accomplish paragraphs (a)(1)(i) and (a)(1)(ii) of this AD.

    (i) Repair in accordance with Chapter 20-30-01 of the McDonnell Douglas MD-11 Airplane Maintenance Manual. And

    (ii) Install a silicone rubber coated with a glass cloth protective wrap [Douglas Material Specification (DMS) 2109 or equivalent] around the wire bundle(s) in the area over frame 1681 above stringer R46 in accordance with Chapter 20-10-01 of the McDonnell Douglas MD-11 Wiring Diagram Manual.

  (2) If the bracket or clamp is not installed: Prior to further flight, perform a visual inspection to detect damage (i.e., chafing, damage, or missing wire insulation) of the subject wire bundle(s).

    (i) If no damage is detected: Prior to further flight, install a silicone rubber coated with a glass cloth protective wrap (DMS 2109 or equivalent) around the wire bundle(s) in the area over frame 1681 above stringer R46 in accordance with Chapter 20-10-01 of the McDonnell Douglas MD-11 Wiring Diagram Manual.

    (ii) If any damage is detected: Prior to further flight, accomplish the actions required by paragraphs (a)(1)(i) and (a)(1)(ii) of this AD.

### (b)

  (b) Within 10 days after accomplishing the inspection required by paragraphs (a) and (a)(1) 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.

### (c)

  (c) 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO.

### (d)

  (d) 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.

### (e)

  (e) This amendment becomes effective on May 5, 1999, to all persons except those persons to whom it was made immediately effective by emergency AD 99-09-51, issued on April 16, 1999, which contained the requirements of this amendment.

[graphic omitted; see the official PDF]

Issued in Renton, Washington, on April 23, 1999. Darrell M. Pederson, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

## Rule preamble

### Dates

Effective May 5, 1999, to all persons except those persons to whom it was made immediately effective by emergency AD 99-09-51, issued on April 16, 1999, which contained the requirements of this amendment.

Comments for inclusion in the Rules Docket must be received on or before June 29, 1999.

### Addresses

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 99-NM-100-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Information pertaining to this amendment may be examined at the Federal Aviation Administration (FAA), Transport Airplane Directorate, Rules Docket, 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, ANM-130L, FAA, Transport Airplane Directorate, Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, Lakewood, California 90712; telephone (562) 627-5350; fax (562) 627-5210.

### Supplementary information

On April 16, 1999, the FAA issued emergency AD 99-09-51, which is applicable to certain McDonnell Douglas Model MD-11 series airplanes.

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 insulation blanket between frames 1661 and 1681 in the lower center cargo compartment was found to be burnt. This incident occurred on a McDonnell Douglas Model MD-11 series airplane.

Investigation revealed that a wiring harness (including wires with a 115 volt alternating current) of the aft cargo loader control unit was contacting the insulation blanket and rubbing against frame 1681 above stringer R46. A wire was cut, and three other wires were missing insulation. In addition, frame 1681 had signs of arcing damage. Furthermore, the exposed moisture barrier material of the insulation blanket was burnt, and a hole was detected on the insulation blanket where the wiring harness was chafing against frame 1681. Further investigation revealed that a wiring harness support bracket/clamp on the wire bundle at frame 1681 may not have been installed during production of the airplane.

This incident 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.

A missing wiring harness support bracket/clamp on the wire bundle at frame 1681 could cause the wire bundle to chafe against the frame, which could result in sparks, smoke, and possible fire in the lower center cargo compartment.

### Other Related Rulemaking

On April 9, 1999, the FAA issued a similar action (AD 99-08-51), which applies only to airplanes that are equipped with a 72-inch cargo door and use the light-weight cargo handling system. However, since the issuance of AD 99-08-51, the FAA has determined that the wire routing on airplanes that are equipped with a 72-inch cargo door and use any cargo handling system must also be inspected. Therefore, the FAA has determined that these additional airplanes also are subject to the unsafe condition identified in AD 99-08-51, and that the actions required by that AD must be accomplished on those airplanes to ensure an adequate level of safety of the affected fleet. Those airplanes are listed in the applicability of this new AD.

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 airworthiness directive 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.

### Explanation of Requirements of the Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of this same type design, this airworthiness directive is issued to require a visual inspection to verify that, under the floorboards in the lower center cargo compartment at frame 1681, a certain bracket and a certain open face nylon clamp are installed to a specific support wire bundle. This AD also requires a visual inspection to detect damage of the subject wire bundle; repair of damaged wiring; and installation of certain silicone rubber coated with a glass cloth protective wrap around the subject wire bundle, if necessary. In addition, this AD requires that operators submit a report of the inspection results to the FAA. The repairs are required to be accomplished in accordance with the procedures specified in Chapter 20-30-01 of the McDonnell Douglas MD-11 Airplane Maintenance Manual, and Chapter 20-10-01 of the McDonnell Douglas MD-11 Wiring Diagram Manual.

Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual notices issued on April 16, 1999, to all known U.S. owners and operators of certain McDonnell Douglas Model MD-11 series airplanes. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective to all persons.

### Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the 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 that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: ``Comments to Docket Number 99-NM-100-AD.'' The postcard will be date stamped and returned to the commenter.

### Regulatory Impact

The regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a ``significant regulatory action'' under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from 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.

### Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

No proposed rule in this release led to it. Its text cites no advisory circulars or STCs.

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