AD 94-24-03

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model DC-10-10, -15, -30, and -40 series airplanes, KC-10A (military) airplanes, and Model MD-11 series airplanes, that requires the installation of retainers and supports at the lateral control mixer bracket on the center of the wing rear spar of the airplane. This amendment is prompted by an analysis conducted by the manufacturer, which revealed that failure of a lateral control mixer bracket could result in uncommanded deployment of the spoiler. The actions specified by this AD are intended to prevent inadvertent asymmetric deployment of the spoiler, which may lead to reduced controllability of the airplane.

Final rule.

94-24-03 McDONNELL DOUGLAS: Amendment 39-9076. Docket 94-NM-26-AD. \n\n\tApplicability: Model DC-10-10, -15, -30, and -40 series airplanes and KC-10A (military) airplanes, as listed in McDonnell Douglas DC-10 Service Bulletin 27-222, dated November 1, 1993; and Model MD-11 series airplanes, as listed in McDonnell Douglas MD-11 Service Bulletin 27-34, dated November 1, 1993; certificated in any category. \n\n\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent inadvertent asymmetric deployment of the spoiler, which may lead to reduced controllability of the airplane, accomplish the following: \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/operatormust use the authority provided in paragraph (b) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition; or different actions necessary to address the unsafe condition described in this AD. Such a request should include an assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any airplane from the applicability of this AD. \n\n\t(a)\tWithin 18 months after the effective date of this AD, install retainers and supports at the lateral control right- and left-hand mixer bracket on the center of the wing rear spar of the airplane in accordance with McDonnell Douglas DC-10 Service Bulletin 27-222, dated November 1, 1993 (for Model DC-10-10, -15, -30, and -40 series airplanes and KC-10A (military) airplanes); or McDonnell Douglas MD-11 Service Bulletin 27-34, dated November 1, 1993 (for Model MD-11 series airplanes); as applicable. \n\n\t(b)\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 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\n\t(c)\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\n\t(d)\tThe installation shall be done in accordance with McDonnell Douglas DC-10 Service Bulletin 27-222, dated November 1, 1993 (for Model DC-10-10, -15, -30, and -40 series airplanes and KC-10A (military) airplanes); and McDonnell Douglas MD-11 Service Bulletin 27-34, dated November 1, 1993 (for Model MD-11 series airplanes); 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 McDonnell Douglas Corporation, P.O. Box 1771, Long Beach, California 90801-1771, Attention: Business Unit Manager, Technical Administrative Support, Department L51, M.C. 2-98. 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(e)\tThis amendment becomes effective on January 3, 1995.

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 and MD-11 series airplanes series airplanes was published in the Federal Register on June 7, 1994 (59 FR 29391). That action proposed to require the installation of retainers and supports at the lateral control mixer bracket on the center of the wing rear spar of the airplane. \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\n\tTwo commenters support the proposal. \n\n\tSeveral commenters request that the compliance time for installing the spoiler mixer bracket retainers be extended from the proposed 12 months to 18 or 24 months. These commenters state that such an extension will allow operators to accomplish the installations during a regularly scheduled heavy maintenance visit. This will reduce the impact of non-scheduled maintenance and removal of aircraft from service, and prevent the consequent inconvenience to the traveling public. The commenters point out that safety will not be compromised by extending the compliance time, since the repetitive inspections of the mixer bracket assembly at intervals of 1,500 cycles, as are currently required by AD 92-16-03, will maintain the structural integrity of the mixer bracket assembly in the interim. \n\n\tThe FAA concurs that the compliance time can be extended somewhat. The FAA's intent was that the inspections be conducted during a regularly scheduled maintenance visit for the majority of the affected fleet, when the airplanes would be located at a base where special equipment and trained personnel would be readily available, if necessary. Based on the information supplied by the commenters, the FAA now recognizes that 18 months corresponds more closely to the interval representative of most of the affected operators' normal maintenance schedules. Paragraph (a) of the final rule has been revised to reflect a compliance time of 18 months. The FAA does not consider that this extension will adversely affect safety, since the mandatory repetitive inspections of the area, as required by AD 92-16-03 will ensure that any discrepancies will be identified and corrected in the interim. \n\n\tThe FAA has recently reviewed the figures it has used over the past several years in calculating the economic impact of AD activity. In order to account for various inflationary costs in the airline industry, the FAA has determined that it is necessary to increase the labor rate used in these calculations from $55 per work hour to $60 per work hour. The economic impact information, below has been revised to reflect this increase in the specified hourly labor rate. \n\n\t(NOTE: As a result of recent communications with the Air Transport Association (ATA) of America, the FAA has learned that, in general, some operators may misunderstand the legal effect of AD's on airplanes that are identified in the applicability provision of the AD, but that have been altered or repaired in the area addressed by the AD. Under these circumstances, at least one operator appears to have incorrectly assumed that its airplane was not subject to an AD. On the contrary, all airplanes identified in the applicability provision of an AD are legally subject to the AD. If an airplane has been altered or repaired in the affected area in such a way as to affect compliance with the AD, the owner or operator is required to obtain FAA approval for an alternative method of compliance with the AD, in accordance with the paragraph of each AD that provides for such approvals. A note has been added to this final rule to clarify this requirement.) \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 theadoption of the rule with the changes previously described. The FAA has determined that these changes will neither increase the economic burden on any operator nor increase the scope of the AD. \n\n\tThere are approximately 427 Model DC-10-10, -15, -30, and -40 series airplanes and KC- 10A (military) airplanes of the affected design in the worldwide fleet. The FAA estimates that 241 airplanes of U.S. registry will be affected by this AD, that it will take approximately 3 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $6,497 per airplane. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $1,609,157, or $6,677 per airplane. \n\n\tThere are approximately 114 Model MD-11 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 46 airplanes of U.S. registry will be affected by this AD, that it would take approximately 3 work hours per airplane to accomplish the proposed actions, and that the average labor rate is $60 per work hour. Required parts would cost approximately $6,497 per airplane. Based on these figures, the total cost impact of the proposed AD on U.S. operators of Model MD-11 series airplanes is estimated to be $307,142, or $6,677 per airplane. \n\n\tBased on the figures discussed above, the total cost impact of this AD on U.S. operators is $1,916,299. This total cost impact figure 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. \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\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.\tThe authority citation for part 39 continues to read as follows: \n\nAuthority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. \n\n§ 39.13 - (Amended) \n\n\t2.\tSection 39.13 is amended by adding the following new airworthiness directive: