AD 2000-07-21

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-11 series airplanes, that requires a general visual inspection of wiring behind the control panel of the auxiliary power unit (APU) located in the cockpit to detect chafing; repair if necessary; and modification of the wiring. This amendment is prompted by an incident of chafing of wire bundles of the control module of the APU. The actions specified by this AD are intended to prevent such chafing and resultant arcing due to insufficient clearance between the wire bundles and the airplane structure, which could result in smoke and fire in the flight deck.

Final rule

2000-07-21 MCDONNELL DOUGLAS: Amendment 39-11675. Docket 99-NM-270-AD. \n\n\tApplicability: Model MD-11 series airplanes, as listed in McDonnell Douglas Alert Service Bulletin MD11-24A116, Revision 01, dated October 11, 1999; except for those airplanes on which the modification specified in McDonnell Douglas Service Bulletin MD11-24-116, dated May 14, 1997, has been accomplished; 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 otherwise 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. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent wire chafing of the control panel of the auxiliary power unit (APU) and resultant arcing due to insufficient clearance between the wire bundles and the airplane structure, which could result in smoke and fire in the flight deck, accomplish the following: \n\nInspection\n\t(a)\tWithin 12 months after the effective date of this AD, perform a general visual inspection of wiring behind the control panel of the APU to detect chafing, in accordance with McDonnell Douglas Alert Service Bulletin MD11-24A116, Revision 01, dated October 11, 1999. \n\n\tNOTE 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." \n\n\t\t(1)\tIf no chafing is found, prior to further flight, accomplish the requirements of paragraph (b) of this AD. \n\t\t(2)\tIf any chafing is found, prior to further flight, repair in accordance with the service bulletin and accomplish the requirements of paragraph (b) of this AD. \n\nModification \n\t(b)\tModify the wiring behind the APU control panel (i.e., install sleeving and fiber tying tape over wires) in accordance with McDonnell Douglas Alert Service Bulletin MD11-24A116, Revision 01, dated October 11, 1999. \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)\tThe actions shall be done in accordance with McDonnell Douglas Alert Service Bulletin MD11-24A116, Revision 01, dated October 11, 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 May 19, 2000.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain McDonnell Douglas Model MD-11 series airplanes was published in the Federal Register on February 1, 2000 (65 FR 4793). That action proposed to require a general visual inspection of wiring behind the control panel of the auxiliary power unit (APU) located in the cockpit to detect chafing; repair if necessary; and modification of the wiring. \n\nComments \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\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\tThere are approximately 164 airplanes of the affected design in the worldwide fleet. The FAA estimates that 61 airplanes of U.S. registry will be affected by this AD. It will take approximately 1 work hour per airplane to accomplish the required 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 $3,660, or $60 per airplane. \n\n\tThe FAA also estimates that it will take approximately 1 work hour per airplane to accomplish the required 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 $3,660, 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 requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted. \n\nRegulatory Impact \n\tThe regulations adopted herein will 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 final rule does not have federalism implications under Executive Order 13132. \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\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption of the Amendment \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\t1. The authority citation for part 39 continues to read as follows: \nAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\t2. Section 39.13 is amended by adding the following new airworthiness directive: