AD 98-24-24

This amendment adopts a new airworthiness directive (AD), applicable to certain MD-11 series airplanes, that requires a one-time visual inspection to detect discrepancies of the seat tracks and adjacent structure underneath lavatories, and repair, if necessary. This amendment also requires installation of a non-metallic barrier on the bottom of each lavatory foot fitting, and replacement of existing seat track fittings with new seat track fittings. This amendment is prompted by reports of galvanic corrosion found on the seat tracks at attachment points under certain lavatories. The actions specified by this AD are intended to prevent corrosion of seat tracks and adjacent structure. Corrosion of the seat tracks and adjacent structure could result in shifting of lavatories, which could lead to injury of passengers and crew, as well as damage to aircraft structure and systems.

Final rule.

98-24-24 MCDONNELL DOUGLAS: Amendment 39-10910. Docket 98-NM-71-AD. \n\n\tApplicability: Model MD-11 series airplanes, as listed in McDonnell Douglas Service Bulletin MD11-53-043, Revision 02, dated May 28, 1996; 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 (b) 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 detect and correct corrosion of seat tracks and adjacent structure, which could result in shifting of lavatories causing injury to passengers and crew, as well as damage to aircraft structure and systems, accomplish the following: \n\n\t(a)\tWithin 15 months after the effective date of this AD, conduct a visual inspection to detect discrepancies (i.e., corrosion and breakage) of the seat tracks and adjacent structure at the lavatory locations defined in JAMCO Service Bulletin MD11-25-1010, dated July 12, 1994. \n\n\t\t(1)\tIf no discrepancy is detected, prior to further flight, install a non-metallic barrier on the bottom of each lavatory foot fitting and replace existing seat track fittings with new fittings, in accordance with McDonnell Douglas Service Bulletin MD-11-53-043, Revision 02, dated May 28, 1996. \n\n\t\t(2)\tIf any discrepancy is detected, prior to further flight, repair in accordance with the McDonnell Douglas MD-11 Structural Repair Manual, or in accordance with a method approved by the Manager, Los Angeles Aircraft Certification Office (ACO), FAA, Transport Airplane Directorate. Prior to further flight following accomplishment of the repair, install a non-metallic barrier on the bottom of each lavatory foot fitting and replace existing seat track fittings with new fittings, in accordance with McDonnell Douglas Service Bulletin MD-11-53-043, Revision 02, dated May 28, 1996. \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 ACO. 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 and replacement shall be done in accordance with McDonnell Douglas Service Bulletin MD11-53-043, Revision 02, dated May 28, 1996. 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 The Boeing Company, Douglas Products 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(e)\tThis amendment becomes effective on December 30, 1998.

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 MD-11 series airplanes was published in the Federal Register on September 3, 1998 (63 FR 46934). That action proposed to require a one-time visual inspection to detect discrepancies of the seat tracks and adjacent structure underneath lavatories, and repair, if necessary. The action also proposed to require installation of a non-metallic barrier on the bottom of each lavatory foot fitting, and replacement of existing seat track fittings with new seat track fittings. \n\nComments \n\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\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\n\tThere are approximately 143 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 will take approximately 40 work hours per airplane to accomplish the required inspection, installation, and replacement, and that the average labor rate is $60 per work hour. Required parts will cost less than $1,000 per airplane. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $156,400, or $3,400 per airplane. \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. \n\nRegulatory Impact \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. The authority citation for part 39 continues to read as follows: \n\nAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\n\t2. Section 39.13 is amended by adding the following new airworthiness directive: