AD 99-24-03

This amendment supersedes two existing airworthiness directives (AD), applicable to certain McDonnell Douglas Model MD-11 series airplanes, that currently require inspections in the lower center cargo compartment at frame 1681 to verify that a certain bracket and a certain open face nylon clamp were installed to a specific wire bundle support and to detect damage of the subject wire bundle; and corrective actions, if necessary. This amendment requires a similar inspection and corrective actions required by the existing AD's and removes certain airplanes from the applicability of the existing AD's. This amendment also adds a requirement to install a wire assembly support bracket, clamp, and spacer, or revise the wire assembly support bracket and clamp installation; as applicable. This amendment is prompted by an incident in which the insulation blanket in the lower center cargo compartment was found to be burnt due to a missing wiring harness support bracket/clamp on a wirebundle. The actions specified by this AD are intended to prevent sparks, smoke, and possible fire in the lower center cargo compartment.

Final rule.

99-24-03 MCDONNELL DOUGLAS: Amendment 39-11427. Docket 99-NM-167-AD. Supersedes AD 99-08-51, Amendment 39-11138 and AD 99-09-51, Amendment 39-11154. \n\n\tApplicability: Model MD-11 series airplanes, as listed in McDonnell Douglas Alert Service Bulletin MD11-24A155, dated June 1, 1999; certificated in any category. \n\n\tNOTE 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 (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, therequest should include specific proposed actions to address it. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent sparks, smoke and possible fire in the lower center cargo compartment, accomplish the following: \n\nPhase 1: Inspection and Corrective Actions \n\t(a)\tWithin 30 days after the effective date of this AD, perform an inspection of the wire assembly, structure, and blankets for evidence of arcing burns and chafing damage under the center cargo compartment floor, in accordance with Phase 1 of the Work Instructions of McDonnell Douglas Alert Service Bulletin MD11-24A155, dated June 1, 1999. \n\n\t\t(1)\tCondition 1. If no arcing or chafing damage is detected, prior to further flight, install protective sleeving on the wire assembly in the area of the frame in accordance with the service bulletin. \n\n\t\t(2)\tCondition 2. If any damaged wire, structure, or blanket is detected, prior to further flight, accomplish the actions specified in paragraphs (a)(2)(i), (a)(2)(ii), and (a)(2)(iii) of this AD. \n\n\t\t\t(i)\tRepair damaged wire and structure in accordance with the service bulletin. \n\n\t\t\t(ii)\tRepair or replace any damaged blanket with a new blanket, in accordance with Chapter 25 of the Aircraft Maintenance Manual; however, insulation blankets made of metallized polyethyleneteraphthalate (MPET) may not be used. \n\n\t\t\t(iii)\tInstall protective sleeving on the wire assembly in the area of the frame in accordance with the service bulletin. \n\n\tNOTE 2: Accomplishment of the actions required by AD 99-08-51, amendment 39-11138, and AD 99-09-51, amendment 39-11154, prior to the effective date of this AD is considered acceptable for compliance with the requirements of paragraph (a) of this AD.\n\nPhase 2: Modification \n\t(b)\tWithin 18 months after the effective date of this AD, accomplish the actions specified in paragraph (b)(1) or (b)(2) of this AD, as applicable, in accordance with Phase 2 of the Work Instructions of McDonnellDouglas Alert Service Bulletin MD11-24A155, dated June 1, 1999. \n\n\t\t(1)\tFor airplanes identified as Group 1 in the service bulletin: Install the wire assembly support bracket, clamp, and spacer. \n\n\t\t(2)\tFor airplanes identified as Group 2 in the service bulletin: Revise the wire assembly support bracket and clamp installation.\n\nAlternative Methods of Compliance \n\t(c)\tAn 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 Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. 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. \n\n\tNOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. \n\nSpecial Flight Permits \n\t(d)\tSpecial 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. \n\nIncorporation by Reference \n\t(e)\tExcept as provided by paragraph (a)(2)(ii) of this AD, the actions shall be done in accordance with McDonnell Douglas Alert Service Bulletin MD11-24A155, dated June 1, 1999. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies 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). Copies may be inspected 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; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\n\t(f)\tThis amendment becomes effective on December 27, 1999.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 99-08-51, amendment 39-11138 (64 FR 22544, April 27, 1999), and AD 99-09-51, amendment 39-11154 (64 FR 23179, April 30, 1999), which are applicable to certain McDonnell Douglas Model MD-11 series airplanes, was published in the Federal Register on August 31, 1999 (64 FR 47438). The action proposed to require inspection of the wire assembly, structure, and blankets for evidence of arcing burns and chafing damage under the center cargo compartment floor; installation of protective sleeving on the wire assembly in the area of the frame; and corrective actions, if necessary. For certain airplanes, the action proposed to require installation of a wire assembly support bracket, clamp, and spacer. For certain other airplanes, the action proposal to require revising the wire assembly support bracket and clamp installation. \n\nComments \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the single comment received. \n\n\tThe commenter supports the proposed rule. \n\nConclusion \n\n\tAfter careful review of the available data, including the comment noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed. \n\nCost Impact \n\n\tThere are approximately 183 airplanes of the affected design in the worldwide fleet. The FAA estimates that 63 airplanes of U.S. registry will be affected by this AD. It will take approximately 1 work hour to accomplish the inspection, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the inspection required by this AD on U.S. operators is estimated to be $3,780, or $60 per airplane. It will take approximately 1 work hour to accomplish the modification, at an average labor rate of $60 per work hour. The cost of required parts will be nominal. Based on these figures, the cost impact of the modification required by this AD on U.S. operators is estimated to be $3,780, or $60 per airplane. \n\n\tThe 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. However, the FAA has been advised that manufacturer warranty remedies are available for some labor costs associated with accomplishing the proposed actions. Therefore, the future economic cost impact of this rule on U.S. operators may be less than the cost impact figures indicated above. \n\nRegulatory Impact \n\n\tThe 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. \n\n\tFor the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." \n\nList of Subjects in 14 CFR Part 39 \n\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.\n\n Adoption of the Amendment \n\n\tAccordingly, 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: \n\nPART 39 - AIRWORTHINESS DIRECTIVES \n\n\t1. The authority citation for part 39 continues to read as follows: \n\nAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\n\t2. Section 39.13 is amended by removing amendment 39-11138 (64 FR 22544, April 27, 1999), and amendment 39-11154 (64 FR 23179, April 30, 1999), and by adding a new airworthiness directive (AD), amendment 39-11427, to read as follows: