AD 2001-24-21

This amendment supersedes an existing airworthiness directive (AD), applicable to all McDonnell Douglas Model DC-10 series airplanes, that currently requires a one-time detailed visual inspection to determine if wire segments of the wire bundle routed through the feed through on the aft side of the flight engineer's station are damaged or chafed, and corrective actions, if necessary. This amendment also requires revising the wire bundle support clamp installation at the flight engineer's station. This action is necessary to prevent chafing of the wire bundle located behind the flight engineer's panel caused by the wire bundle coming in contact with the lower edge of the feed through and consequent electrical arcing, which could result in smoke and fire in the cockpit. This action is intended to address the identified unsafe condition.

Final rule

2001-24-21 McDonnell Douglas: Amendment 39-12538. Docket 2001-NM-96-AD. Supersedes AD 2000-10-03, Amendment 39-11727. \n\n\tApplicability: Model DC-10 series airplanes, and Model MD-10-10F and -30F series airplanes; as listed in Boeing Alert Service Bulletin DC10-24A149, Revision 02, dated April 5, 2001; 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, the request should include specific proposed actions to address it. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent chafing of the wire bundle located behind the flight engineer's panel caused by the wire bundle coming in contact with the lower edge of the feed through and consequent electrical arcing, which could result in smoke and fire in the cockpit, accomplish the following: \n\nRestatement of Certain Requirements of AD 2000-10-03 \n\nInspection and Repair, If Necessary \n\n\t(a) Within 1 year after June 21, 2000 (the effective date of AD 2000-10-03, amendment 39-11727), perform a one-time detailed visual inspection to determine if the wire segments of the wire bundle routed through the feed through on the aft side of the flight engineer's station are damaged or chafed, in accordance with McDonnell Douglas Alert Service Bulletin DC10-24A149, Revision 01, dated July 28, 1999, or Boeing Alert Service Bulletin DC10-24A149, Revision 02, datedApril 5, 2001. If any damaged or chafed wire is found, prior to further flight, repair in accordance with the alert service bulletin. \n\n\tNote 2: For the purposes of this AD, a detailed inspection is defined as: "An intensive visual examination of a specific structural area, system, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at intensity deemed appropriate by the inspector. Inspection aids such as mirror, magnifying lenses, etc. may be used. Surface cleaning and elaborate access procedures may be required." \n\nNew Actions Required by this AD \n\nRevision of Wire Bundle Support Clamp Installation \n\n\t(b) Within 1 year after the effective date of this AD, revise the wire bundle support clamp installation at the flight engineer's station, per Boeing Alert Service Bulletin DC10-24A149, Revision 02, dated April 5, 2001. \n\nAlternative Methods of Compliance \n\n\t(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 Aircraft Certification Office (ACO), FAA. 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\n\t(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. \n\nIncorporation by Reference \n\n\t(e) The actions shall be done in accordance with McDonnell Douglas Alert Service Bulletin DC10-24A149, Revision 01, dated July 28, 1999; or Boeing Alert Service Bulletin DC10-24A149, Revision 02, dated April 5, 2001; as applicable. \n\n\t\t(1) The incorporation by reference of Boeing Alert Service Bulletin DC10-24A149, Revision 02, dated April 5, 2001, is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. \n\n\t\t(2) The incorporation by reference of McDonnell Douglas Alert Service Bulletin DC10-24A149, Revision 01, dated July 28, 1999, was approved previously by the Director of the Federal Register as of June 21, 2000 (65 FR 31253, May 17, 2000). \n\n\t\t(3) Copies may be obtained from Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Data and Service Management, Dept. C1-L5A (D800-0024). Copies may be inspected 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; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. \n\nEffective Date \n\n\t(f) This amendment becomes effective on January 16, 2002.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 2000-10-03, amendment 39-11727 (65 FR 31253, May 17, 2000), which is applicable to certain McDonnell Douglas Model DC-10 series airplanes, and Model MD-10-10F and -30F series airplanes was published in the Federal Register on July 23, 2001 (66 FR 38188). The action proposed to continue to require a one-time detailed visual inspection to determine if wire segments of the wire bundle routed through the feed through on the aft side of the flight engineer's station are damaged or chafed, and corrective actions, if necessary. The action also proposed to require revising the wire bundle support clamp installation at the flight engineer's station. \n\nComment Received \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the comment received. \n\nRequest To Withdraw Proposed ADThe commenter requests that the proposed AD be withdrawn. The commenter states that it recently inspected the subject harness installation per AD 2000-10-03 on airplanes with a minimum of 13 years in service and a maximum of 29 years in service. The inspections revealed no chafed or damaged wires or broken support clamps. Therefore, the commenter concludes that the requirements of the proposed AD are unnecessary. \n\n\tThe FAA does not agree. As discussed in the preamble of the proposed AD, we determined that the revision of the wire bundle support clamp installation required by AD 2000-10-03 for certain airplanes does not adequately address the identified unsafe condition. In addition, we determined that all affected airplanes must incorporate this new, improved support clamp, because the procedures specified in McDonnell Douglas Alert Service Bulletin DC10-24A149, Revision 01, dated July 28, 1999 (which was referenced in AD 2000-10-03 as the appropriate source of service information), do not prevent electrical arcing or chafing even if no chafed or damaged wire bundles located behind the flight engineer's panel were found during the required one-time inspection. Therefore, we find that the requirements of this AD are warranted to adequately address the identified unsafe condition. \n\nRequest To Revise Compliance Time \n\n\tIf the AD is issued as proposed, the commenter requests that the compliance time for the proposed revision of the wire bundle support clamp installation be revised from 1 year to 18 months. The commenter states that the work scope of the proposed AD is best suited for "a planned multiple-day maintenance visit." \n\n\tThe FAA does not agree. In developing an appropriate compliance time for this action, we considered not only those safety issues in developing an appropriate compliance time for this action, but the recommendations of the manufacturer, and the practical aspect of accomplishing the required revision within an interval of time that parallels normal scheduled maintenance for the majority of affected operators. In consideration of all of these factors, we determined that the compliance time, as proposed, represents an appropriate interval in which the required revision can be accomplished in a timely manner within the fleet and still maintain an adequate level of safety. \n\n\tIn addition, the FAA finds that operators of affected airplanes on the U.S. Register should have already accomplished the one-time inspection required by paragraph (a) of this AD (the effective date for compliance was June 21, 2001) which is a restatement of the requirements of AD 2000-10-03). Operators are given credit for work previously performed by means of the phrase in the "Compliance" section of the AD that states, "Required as indicated, unless accomplished previously." Therefore, operators should be able to accomplish the additional work of revising the wire bundle support clamp installation required by paragraph (b) of this AD within the 1-year compliance time during regularly scheduled maintenance intervals. However, under the provisions of paragraph (c) of this AD, we may approve requests for adjustments to the compliance time if data are submitted to substantiate that such an adjustment would provide an acceptable level of safety. \n\nRequest To Revise Work Hours \n\n\tThe commenter disagrees with the FAA's estimate of two work hours to accomplish the revision of the wire bundle support clamp installation in the Cost Impact section of the proposed AD. The commenter estimates four work hours per airplane, because of the confined space and numerous wire bundles in the area of the modification. \n\n\tThe FAA does not concur. We used the work hours specified in Boeing Alert Service Bulletin DC10-24A149, Revision 02, dated April 5, 2001 (which is referenced in the AD as the appropriate source of service information for accomplishment of the required modification). We note that the economic analysis of this AD representsthe time necessary to perform only the actions actually required by this AD. We recognize that, in accomplishing the requirements of any AD, operators may incur "incidental" costs in addition to the "direct" costs. As indicated in the preamble of the notice of proposed rulemaking (NPRM), the cost analysis in AD rulemaking actions typically does not include incidental costs, such as the time required to gain access and close up; planning time; or time necessitated by other administrative actions. Because incidental costs may vary significantly from operator to operator, they are almost impossible to calculate. Therefore, no change to the final rule is necessary. \n\nConclusion \n\n\tAfter careful review of the available data, including the comments 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 412 Model DC-10 series airplanes and Model MD-10-10F and -30F series airplanes of the affected design in the worldwide fleet. The FAA estimates that 300 airplanes of U.S. registry will be affected by this AD. \n\n\tThe actions that are currently required by AD 2000-10-03, and retained in this AD, take approximately 1 work hour per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the currently required actions on U.S. operators is estimated to be $18,000, or $60 per airplane. \n\n\tThe new actions that are required in this AD action will take approximately 2 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the new requirements of this AD on U.S. operators is estimated to be $36,000, or $120 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 ifthis 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. \n\nRegulatory Impact \n\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\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoption 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\n\tAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\nSec. 39.13 (Amended) \n\n\t2. Section 39.13 is amended by removing amendment 39-11727 (65 FR 31253, May 17, 2000), and by adding a new airworthiness directive (AD), amendment 39-12538, to read as follows: