AD 95-10-02

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas MD-11 series airplanes, that requires the installation of an electrically controlled slat system. This amendment is prompted by numerous incidents of inadvertent deployment of the slats while the airplane was in flight at cruise altitude. The actions specified by this AD are intended to prevent inadvertent deployment of the slats during flight, which could result in an abrupt pitch up of the airplane and consequent injury to crew and passengers; it could also result in significant vibrations and cause damage to the elevators.

Final rule.

95-10-02 McDONNELL DOUGLAS: Amendment 39-9219. Docket 94-NM-175-AD. \n\n\tApplicability: Model MD-11 series airplanes; as listed in McDonnell Douglas MD-11 Service Bulletin 27-36, Revision 1, dated December 9, 1994, 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 use the authority provided in paragraph (c) 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\tCompliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent inadvertent deployment of the slats during flight, accomplish the following: \n\n\t(a)\tWithin 24 months after the effective date of this AD, modify the airplane and install an electrically controlled slat control system in accordance with McDonnell Douglas MD-11 Service Bulletin 27-36, Revision 1, dated December 9, 1994. \n\n\t(b)\tAccomplishment of the actions required by paragraph (a) of this AD constitutes terminating action for the requirements of the following AD's: \n\n\nAD\nNumber\nAmendment \nNumber\nFederal Register \nCitation\n 92-13-03\t\t\n39-8273\n(57 FR 27155, June 18, 1992) \n92-14-51\t\n39-8325\t\n(57 FR 38264, August 24, 1992)\n 92-26-03\t\n39-8430\t\n(57 FR 57906, December 8, 1992)\n 93-15-03\t\n\n39-8649\t\n(58 FR 41421, August 4, 1993)(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 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(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\n\t(e)\tThe installation shall be done in accordance with McDonnell Douglas MD-11 Service Bulletin 27-36, Revision 1, dated December 9, 1994. 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, Dept. 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, Los Angeles Aircraft Certification Office, Transport Airplane Directorate, 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 June 12, 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 Model MD-11 series airplanes; as listed in McDonnell Douglas MD-11 Service Bulletin 27-36, Revision 1, dated December 9, 1994 was published in the Federal Register on January 6, 1995 (60 FR 2041). That action proposed to require installation of an electrically controlled slat system. \n\n\tInterested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the two comments received. \n\n\tOne commenter supports the proposed rule. \n\n\tThe other commenter supports the rule, but disagrees with the FAA's estimate of the number of work hours that would be required to accomplish the installation. In the preamble to the proposal, the FAA indicated that the time necessary to perform the installation would be approximately 68 work hours; however, the commenter indicates that a more reasonable estimate is closer to 200 work hours. The FAA does not concur with the commenter's revised estimate, since the commenter provided no additional information to support it. The FAA's original estimate of labor time was based on data provided by the manufacturer at the time the proposal was developed. Upon further review of that data, however, the FAA finds that the most accurate estimate of the time necessary to accomplish the installation is 75 work hours. This number includes 4 work hours to gain access; 8 work hours to remove components; 51 work hours for modification of mechanical and electrical components; 4 work hours for installation; 4 work hours for closing up; and 4 work hours for a functional check. The cost analysis information, described below, has been revised to indicate that 75 work hours are necessary for accomplishment of the required installation. In general, the cost analysis in AD rulemaking actions typically does not include planning time, time for administrative functions, nonproductive elapsed time, or aircraft preparation time. \n\n\tAs 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. The FAA points out that 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 long-standing 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 the adoption 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 124 Model MD-11 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 43 airplanes of U.S. registry will be affected by this AD, that it will take approximately 75 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will be supplied by the manufacturer at no charge to operators. Based on these figures, the total cost impact of the AD on U.S. operators is estimated to be $193,500, or $4,500 per airplane. \n\n\tThe total cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirementsof 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: