AD 2000-07-20

This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas Model MD-11 series airplanes, that requires electrical resistance measurements of the ground studs of the No. 2 generator in the electrical power center of the center accessory compartment for proper electrical bonding and of the ground studs and circuit breaker terminations in the forward cargo compartment to detect looseness and for proper electrical bonding; and corrective actions, if necessary. This amendment is prompted by an incident of charred insulation blankets in the forward cargo compartment in the area of the external ground power receptacle and the galley external power circuit breakers, and another incident of a No. 2 "generator off" alert while the generator was still on line. The actions specified by this AD are intended to prevent arcing and overheating of terminals and consequent smoke and fire in the forward cargo compartment due to improper bonding of groundstuds in the forward cargo compartment and in the electrical power center and due to improper installation of circuit breaker terminations.

Final rule

2000-07-20 MCDONNELL DOUGLAS: Amendment 39-11674. Docket 99-NM-269-AD. \n\n\tApplicability: Model MD-11 series airplanes, as listed in McDonnell Douglas Alert Service Bulletin MD11-24A040, Revision 01, dated October 11, 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 (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.Compliance: Required as indicated, unless accomplished previously. \n\n\tTo prevent arcing and overheating of terminals and consequent smoke and fire in the forward cargo compartment due to improper bonding of ground studs in the forward cargo compartment and in the electrical power center (EPC) and due to improper installation of circuit breaker terminations, accomplish the following: \n\nResistance Check and Corrective Actions \n\t(a)\tWithin 12 months after the effective date of this AD, accomplish the actions specified in paragraphs (a)(1) and (a)(2) of this AD, in accordance with McDonnell Douglas Alert Service Bulletin MD11-24A040, Revision 01, dated October 11, 1999. \n\n\t\t(1)\tPerform an electrical resistance measurement of the ground studs of the No. 2 generator in the electrical power center of the center accessory compartment for proper electrical bonding, in accordance with the service bulletin. \n\n\t\t\t(i)\tIf all ground studs are electrically bonded properly, prior to further flight, tighten applicable fasteners, if necessary, in accordance with the service bulletin. \n\n\t\t\t(ii)\tIf any ground stud is not electrically bonded properly, prior to further flight, electrically bond the ground stud in accordance with the service bulletin. \n\n\t\t(2)\tPerform an electrical resistance measurement of the ground studs and circuit breaker terminations in the forward cargo compartment to detect looseness and for proper electrical bonding, in accordance with the service bulletin. \n\n\t\t\t(i)\tIf all ground studs are electrically bonded properly, prior to further flight, tighten applicable attaching parts in accordance with the service bulletin. \n\n\t\t\t(ii)\tIf any circuit breaker termination is found loose, tighten in accordance with the service bulletin. \n\n\t\t\t(iii)\tIf any ground stud is not electrically bonded properly, prior to further flight, electrically bond the ground stud in accordance with the service bulletin. \n\nAlternative Methods of Compliance \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\nSpecial Flight Permits \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\nIncorporation by Reference \n\t(d)\tThe actions shall be done in accordance with McDonnell Douglas Alert Service Bulletin MD11-24A040, Revision 01, dated October 11, 1999. 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: 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 May 19, 2000.

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 MD-11 series airplanes was published in the Federal Register on February 1, 2000 (65 FR 4792). That action proposed to require electrical resistance measurements of the ground studs of the No. 2 generator in the electrical power center of the center accessory compartment for proper electrical bonding and of the ground studs and circuit breaker terminations in the forward cargo compartment to detect looseness and for proper electrical bonding; and corrective actions, if necessary. \n\nComments\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\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\tThere are approximately 31 airplanes of the affected design in the worldwide fleet. The FAA estimates that 9 airplanes of U.S. registry will be affected by this AD. It will take approximately 2 work hours per airplane to accomplish the required measurements, at an average labor rate of $60 per work hour. Based on these figures, the cost impact of the measurements required by this AD on U.S. operators is estimated to be $1,080, or $120 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\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 location provided under the caption "ADDRESSES." \n\nList of Subjects in 14 CFR Part 39 \n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. \n\nAdoptionof the Amendment \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\t1. The authority citation for part 39 continues to read as follows: \nAuthority: 49 U.S.C. 106(g), 40113, 44701. \n\n§ 39.13 (Amended) \n\t2. Section 39.13 is amended by adding the following new airworthiness directive: