AD 97-09-07

This amendment supersedes an existing airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-11 series airplanes, that currently requires inspections to detect damage of the support brackets and clamps of the transfer pipe of the tail tank, and of the transfer pipe assembly; and replacement of damaged parts, or installation of a doubler, if necessary. This amendment adds a requirement to install a fuel transfer pipe of the tail tank, and to install support brackets and clamps of the fuel feed pipe of engine No. 2, which constitutes terminating action for the repetitive inspections. This amendment also requires, for certain airplanes, removal of a temporary protective doubler installed on the fuel pipe assembly. This amendment is prompted by reports of cracking of the support brackets in the refuel and fuel transfer lines of the tail fuel tank and damage to the nylon clamps and transfer pipe assembly. The actions specified by this AD are intended toprevent such cracking and damage, which could result in further damage to the transfer pipe assembly and possible fuel leakage.

Final rule.

97-09-07 MCDONNELL DOUGLAS: Amendment 39-10003. Docket 96-NM-278-AD. Supersedes AD 96-10-07, Amendment 39-9612. \n\n\tApplicability: Model MD-11 series airplanes; as listed in McDonnell Douglas Service Bulletin MD11-28-089, dated October 24, 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 otherwise 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)(1) 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 cracking of the support brackets in the refuel and fuel transfer lines of the tail fuel tank and damage to the nylon clamps and transfer pipe assembly, which, if not corrected, could result in further damage to the transfer pipe assembly and possible fuel leakage, accomplish the following: \n\nRestatement of Requirements of AD 96-10-07 \n\n\t(a)\tFor Group 1 airplanes listed in McDonnell Douglas Alert Service Bulletin MD11-28A083, dated March 13, 1996: Within 90 days after May 24, 1996 (the effective date of AD 96-10-07, amendment 39-9612), accomplish the requirements of paragraphs (a)(1) and (a)(2) of this AD in accordance with Paragraph 3. of the Accomplishment Instructions of McDonnell Douglas Alert Service Bulletin MD11-28A083, dated March 13, 1996, or McDonnell Douglas Alert Service Bulletin MD11-28A083, Revision 01, dated May 29, 1996. \n\n\t\t(1)\tPerform a visual inspection for cracking, bending, or stress of the support brackets and damage to the nylon clamps of the transfer pipe of the tail tank, in accordance with the alert service bulletin. If any damaged bracket or clamp is detected, prior to further flight, replace it with a serviceable part in accordance with the alert service bulletin. \n\n\t\t(2)\tPerform a visual inspection for chafing and/or denting of the transfer pipe assembly of the tail tank, in accordance with the alert service bulletin. \n\n\t\t\t(i)\tCondition 1. If no damage to the fuel pipe assembly is detected, accomplish the requirements of either paragraph (a)(2)(i)(A) or (a)(2)(i)(B) of this AD at the times specified in that paragraph. \n\n\t\t\t\t(A)\tCondition 1, Option 1. Thereafter, repeat the visual inspections required by paragraph (a) of this AD at intervals not to exceed 600 flight hours; or \n\n\t\t\t\t(B)\tCondition 1, Option 2. Install a temporary doubler on the fuel pipe assembly in accordance with the alert service bulletin and, thereafter, repeat the visual inspections required by paragraph (a) of this AD at intervals not to exceed 15 months. \n\n\t\t\t(ii)\tCondition 2. If damage is found that is within the limits specified by the alert service bulletin, prior to further flight, install a temporary doubler on the fuel pipe assembly. Thereafter, repeat the visual inspections required by paragraph (a) of this AD at intervals not to exceed 15 months. \n\n\t\t\t(iii)\tCondition 3. If damage is found that is outside the limits specified by the alert service bulletin, prior to further flight, replace the fuel pipe assembly with a new or serviceable assembly; and accomplish the requirements of either paragraph (a)(2)(iii)(A) or (a)(2)(iii)(B) of this AD at the time specified in that paragraph. \n\n\t\t\t\t(A)\tCondition 3, Option 1. Thereafter, repeat the visual inspections required by paragraph (a) of this AD at intervals not to exceed 600 flight hours; or \n\n\t\t\t\t(B)\tCondition 3, Option 2. Install a temporarydoubler on the fuel pipe assembly; and repeat the visual inspections required by paragraph (a) of this AD, thereafter, at intervals not to exceed 15 months. (Replacement of the fuel pipe assembly with a serviceable pipe assembly that has been repaired by welding a doubler in the area of potential damage, does not require the installation of a temporary doubler.) \n\nNew Requirements of this AD \n\n\t(b)\tWithin 24 months after the effective date of this AD, accomplish the requirements of paragraphs (b)(1) and (b)(2) of this AD, as applicable. \n\n\t\t(1)\tFor airplanes on which the temporary protective doubler has been installed on the fuel pipe assembly in accordance with McDonnell Douglas Alert Service Bulletin MD11-28A083, dated March 13, 1996: Remove the clamps and the temporary protective doubler installed on the fuel transfer pipe, in accordance with McDonnell Douglas Service Bulletin MD11-28-089, dated October 24, 1996. Prior to further flight following accomplishment of the removal, accomplish the requirements of paragraph (a)(2) of this AD. \n\n\t\t(2)\tFor all airplanes: Install the fuel transfer pipe of the tail tank and support brackets and clamps of the fuel feed pipe of engine No. 2, in accordance with McDonnell Douglas Service Bulletin MD11-28-089, dated October 24, 1996. Accomplishment of this installation constitutes terminating action for the requirements of this AD. \n\n\t(c)\t(1)\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\t\t(2)\tAlternative methods of compliance that concern the use of an alternate material in lieu of the specified temporary doubler, which were approved previously inaccordance with AD 96-10-07, amendment 39-9612, are not considered to be approved as alternative methods of compliance with this AD. \n\n\t(d)\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(e)\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(f)\tCertain actions shall be done in accordance with McDonnell Douglas Alert Service Bulletin MD11-28A083, dated March 13, 1996, or McDonnell Douglas Alert Service Bulletin MD11-28A083, Revision 01, dated May 29, 1996. Certain other actions shall be done in accordance with McDonnell Douglas Service Bulletin MD11-28-089, dated October 24, 1996. The incorporation by reference of McDonnell Douglas Alert Service Bulletin MD11-28A083, dated March 13, 1996, was approved previously by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51 as of May 24, 1996 (61 FR 21066, May 9, 1996). The incorporation by reference of the remainder of the service documents listed above is 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, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Technical Publications Business Administration, Department C1-L51 (2-60). Copies may beinspected 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(g)\tThis amendment becomes effective on June 6, 1997.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) by superseding AD 96-10-07, amendment 39-9612 (61 FR 21066, May 9, 1996), which is applicable to certain McDonnell Douglas Model MD-11 series airplanes, was published in the Federal Register on February 18, 1997 (62 FR 7180). The action proposed to supersede AD 96-10-07 to continue to require visual inspections to detect cracking, bending, or stress of the support brackets and damage to the nylon clamps of the transfer pipe of the tail tank. It also proposed to continue to require repetitive inspections to detect damage of the support brackets and clamps. \n\n\tHowever, for certain airplanes, this AD adds a requirement to remove certain clamps and the temporary protective doubler on the fuel pipe assembly. It also requires installation of a fuel transfer pipe of the tail tank, and installation of support brackets and pipe clamps of the fuel feed pipe on engine No. 2, which constitutes terminating action for the repetitive inspections. \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\tBoth commenters support the proposed rule. \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. Cost Impact \n\n\tThere are approximately 145 Model MD-11 series airplanes of the affected design in the worldwide fleet. The FAA estimates that 40 airplanes of U.S. registry will be affected by this proposed AD. \n\n\tThe actions that are currently required by AD 96-10-07 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 currently required actions on U.S. operators is estimated to be $4,800, or $120 per airplane, per inspection cycle. \n\n\tThe new actions that are required by this new AD will take approximately 6 work hours per airplane to accomplish, at an average labor rate of $60 per work hour. Required parts will cost approximately $691 per airplane. Based on these figures, the cost impact of the new requirements of this AD on U.S. operators is estimated to be $42,040, or $1,051 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 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 removing amendment 39-9612 (61 FR 21066, May 9, 1996), and by adding a new airworthiness directive (AD), amendment 39-10003, to read as follows: