AD 2001-14-08

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-10 series airplanes, Model MD-10 series airplanes, and Model MD-11 series airplanes, that requires repetitive inspections of the number 1 and 2 electric motors of the auxiliary hydraulic pump for electrical resistance, continuity, mechanical rotation, and associated wiring resistance/voltage; and corrective actions, if necessary. This amendment is necessary to prevent various failures of electric motors of the auxiliary hydraulic pump and associated wiring, which could result in fire at the auxiliary hydraulic pump and consequent damage to the adjacent electrical equipment and/or structure. This action is intended to address the identified unsafe condition.

Final rule.

2001-14-08 McDonnell Douglas: Amendment 39-12319. Docket 2000-NM-269-AD. \n\n\tApplicability: Model DC-10 and MD-10 series airplanes, as listed in McDonnell Douglas Alert Service Bulletin DC10-29A142, Revision 01, dated October 21, 1999; and Model MD-11 series airplanes, as listed in McDonnell Douglas Alert Service Bulletin MD11-29A057, Revision 01, dated October 21, 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 (e) 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 various failures of electric motors of the auxiliary hydraulic pump and associated wiring, which could result in fire at the auxiliary hydraulic pump and consequent damage to the adjacent electrical equipment and/or structure, accomplish the following: \n\nInspection \n\n\t(a) Do a detailed inspection of the number 1 and 2 electric motors of the auxiliary hydraulic pump for electrical resistance, continuity, mechanical rotation, and associated wiring resistance/ voltage, per McDonnell Douglas Alert Service Bulletin DC10-29A142, Revision 01, dated October 21, 1999 (for Model DC-10 and MD-10 series airplanes); or McDonnell Douglas Alert Service Bulletin MD11-29A057, Revision 01, dated October 21, 1999 (for Model MD-11 series airplanes); as applicable; at the applicable time specified in paragraph (a)(1) or (a)(2) of this AD. \n\n\t\t(1) For Model DC-10 and MD-10 series airplanes: Inspect within 6 months after the effective date of this AD. \n\n\t\t(2) For Model MD-11 series airplanes that have accumulated 3,000 flight hours or more as of the effective date of this AD: Inspect within 6 months after the effective date of this AD. \n\n\t\t(3) For Model MD-11 series airplanes that have accumulated less than 3,000 flight hours as of the effective date of this AD: Inspect within 6 months after accumulating 3,000 flight hours. \n\nCondition 1, No Failures: Repetitive Inspections \n\n\t(b) If no failures are detected during the inspection required by paragraph (a) of this AD, repeat the inspection required by paragraph (a) of this AD every 6,000 flight hours or every 18 months, whichever occurs first. \n\nCondition 2, Failure of Any Pump Motor: Replacement and Repetitive Inspections \n\n\t(c) If any pump motor fails during any inspection required by paragraph(a) of this AD, before further flight, replace the auxiliary hydraulic pump with a serviceable pump, per McDonnell Douglas Alert Service Bulletin DC10-29A142, Revision 01, dated October 21, 1999 (for Model DC-10 and MD-10 series airplanes); or McDonnell Douglas Alert Service Bulletin MD11-29A057, Revision 01, dated October 21, 1999 (for Model MD-11 series airplanes); as applicable. Repeat the inspection required by paragraph (a) of this AD every 6,000 flight hours or every 18 months, whichever occurs first. \n\nCondition 3, Failure of Any Wiring: Repair and Repetitive Inspections \n\n\t(d) If any wiring fails during any inspection required by paragraph (a) of this AD, before further flight, troubleshoot and repair the wiring, per McDonnell Douglas Alert Service Bulletin DC10-29A142, Revision 01, dated October 21, 1999 (for Model DC-10 and MD-10 series airplanes); or McDonnell Douglas Alert Service Bulletin MD11-29A057, Revision 01, dated October 21, 1999 (for Model MD-11 series airplanes); as applicable. Repeat the inspection required by paragraph (a) of this AD every 6,000 flight hours or every 18 months, whichever occurs first. \n\nAlternative Methods of Compliance \n\n\t(e) 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 2: 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 Permit \n\n\t(f) 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(g) The actions shall be done in accordance with McDonnell Douglas Alert Service Bulletin DC10-29A142, Revision 01, dated October 21, 1999; or McDonnell Douglas Alert Service Bulletin MD11-29A057, Revision 01, dated October 21, 1999; as applicable. 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: 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(h) This amendment becomes effective on August 16, 2001.

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 DC-10 series airplanes, Model MD-10 series airplanes, and Model MD-11 series airplanes was published in the Federal Register on November 27, 2000 (65 FR 70671). That action proposed to require repetitive inspections of the number 1 and 2 electric motors of the auxiliary hydraulic pump for electrical resistance, continuity, mechanical rotation, and associated wiring resistance/voltage; and corrective actions, if necessary. \n\nComments 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 comments received. \n\nRequests to Extend the Compliance Times \n\n\tOne commenter requests that the initial inspection be revised to within 18 months after the effective date of the AD, and the repetitive inspections to every 18 months thereafter. The commenter states that its "light check" (LCK) is accomplished every 18 months, and that such a multiple-day maintenance visit is more appropriate for the type of detailed inspection specified in the proposed rule. The commenter notes that such a revision to the compliance times would simplify its ability to perform the inspection during an appropriate maintenance visit. The commenter also states that experience indicates that a mean time of 12,192 flight hours occurs between unscheduled removal of the auxiliary hydraulic pump. Therefore, performing repetitive inspections in conjunction with the LCK would result in inspections occurring at approximately every 6,000 hours, which is less than half the current mean time between unit removals (MTBUR). Further, the commenter concludes that adjustment of the repetitive interval to every 18 months would provide an equivalent level of safety. \n\n\tThe FAA partially agrees with the commenter's request. In developing the proposed compliance times for this AD action, we considered not only the degree of urgency associated with the addressing the subject unsafe condition, but also the practical aspect of incorporating the required inspections into the affected operators' maintenance schedules in a timely manner. Based on the information submitted by the commenter, we have determined that extending the repetitive inspection interval to every 6,000 flight hours or 18 months, whichever occurs first, will provide an acceptable level of safety. The final rule has been revised accordingly. However, in consideration of the urgency of the unsafe condition in this case, we can find no basis to allow similar escalation for the initial inspection. \n\n\tAnother commenter requests that the initial compliance time be extended to 9 or 12 months. The commenter expresses a concern that there may not be enough spare auxiliary pumps to support the compliance times specified in the proposed rule.The FAA does not concur with the commenter's request based on its concern for spare parts availability. We have had no confirmation from the manufacturer that a problem exists with the availability of the auxiliary pumps. However, under paragraph (e) of this AD, a request for an alternative method of compliance may be submitted to the FAA if availability of the pumps should become a concern in the future. \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 with the change previously described. The FAA has determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD. \n\nInterim Action \n\n\tThis is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking. \n\nCost Impact \n\n\tThere are approximately 604 Model DC-10, MD-10,and MD-11 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 396 airplanes of U.S. registry will be affected by this AD, that it will take approximately 1 work hour per airplane to accomplish the required inspection, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $23,760, or $60 per airplane, per inspection cycle. \n\n\tThe cost impact figure discussed above is 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. 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 locationprovided 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 adding the following new airworthiness directive: