AD 2000-20-04

This document supersedes an existing airworthiness directive (AD) that applies to certain McDonnell Douglas Model MD-90-30 series airplanes. That AD currently requires replacement of certain ground block screws with new screws; and retermination of the circuit ground wires of the electrical power control unit (EPCU) to separate grounding points. The actions specified in that AD are intended to prevent a loose electrical ground block of the circuit ground wires of the EPCU, which could result in complete loss of the primary electrical power of an airplane during flight. This amendment is prompted by the Federal Aviation Administration's determination that the existing AD must be revised to ensure that the requirements apply to the appropriate airplane groups. \n\n\tThe incorporation by reference of McDonnell Douglas Service Bulletin MD90-24-062, dated February 3, 2000, as listed in the regulations, is approved by the Director of the Federal Register as of November 13, 2000.The incorporation by reference of McDonnell Douglas Alert Service Bulletin MD90-24A060, Revision 01, dated September 2, 1999, as listed in the regulations, was approved previously by the Director of the Federal Register as of September 19, 2000 (65 FR 49728, August 15, 2000).

Final rule; correction

2000-20-04 MCDONNELL DOUGLAS: Amendment 39-11915. Docket 99-NM-329-AD. Supersedes AD 2000-16-01, Amendment 39-11855.\n\n\tApplicability: Model MD-90-30 series airplanes, as listed in McDonnell Douglas Alert Service Bulletin MD90-24A060, Revision 01, dated September 2, 1999, and McDonnell Douglas Service Bulletin MD90-24-062, dated February 3, 2000; 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 (c) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by thisAD; 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 a loose electrical ground block of the circuit ground wires of the electrical power control unit (EPCU), accomplish the following: \n\nReplacement\n\t(a) For airplanes listed in McDonnell Douglas Alert Service Bulletin MD90-24A060, Revision 01, dated September 2, 1999: Within 30 days after the effective of this AD, replace the electrical ground block screws with new screws in accordance with McDonnell Douglas Alert Service Bulletin MD90-24A060, Revision 01, dated September 2, 1999.\n\n\tNote 2: Accomplishment of the replacement of electrical ground block screws prior to the effective date of this AD in accordance with McDonnell Douglas Alert Service Bulletin MD90-24A060, dated July 28, 1999, is acceptable for compliance with the requirements of paragraph (a) of this AD.Modification of the Electrical Power Control Unit \n\t(b) For airplanes listed in McDonnell Douglas Service Bulletin MD90-24-062, dated February 3, 2000: Within 12 months after the effective date of this AD, reterminate the circuit ground wires of the EPCU to separate grounding points to ensure that a single point failure does not occur, in accordance with McDonnell Douglas Service Bulletin MD90-24-062, dated February 3, 2000.\n\nAlternative Methods of Compliance\n\t(c) An 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. 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 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from theLos Angeles ACO.\n\nIncorporation by Reference\n\t(d) The actions shall be done in accordance with McDonnell Douglas Alert Service Bulletin MD90-24A060, Revision 01, dated September 2, 1999; and McDonnell Douglas Service Bulletin MD90-24-062, dated February 3, 2000; as applicable. \n\n\t\t(1) The incorporation by reference of McDonnell Douglas Service Bulletin MD90-24-062, dated February 3, 2000, is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51.\n\n\t\t(2) The incorporation by reference of McDonnell Douglas Alert Service Bulletin MD90-24A060, Revision 01, dated September 2, 1999, was approved previously by the Director of the Federal Register as of September 19, 2000 (65 FR 49728, August 15, 2000). \n\n\t\t(3) 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, Los Angeles ACO, 3960 Paramount Boulevard, Lakewood, California; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.\n\nEffective Date\n\t(e) This amendment becomes effective on November 13, 2000.

On August 3, 2000, the Federal Aviation Administration (FAA) issued AD 2000-16-01, amendment 39-11855 (65 FR 49728, August 15, 2000), which applies to certain McDonnell Douglas Model MD-90-30 series airplanes. That AD requires replacement of certain ground block screws with new screws; and retermination of the circuit ground wires of the electrical power control unit (EPCU) to separate grounding points. That AD was prompted by reports of complete loss of the primary electrical power on an airplane during flight. The actions required by that AD are intended to prevent a loose electrical ground block of the circuit ground wires of the EPCU, which could result in complete loss of the primary electrical power of an airplane during flight.\n\nNeed for the Correction\n\tIn the preamble of AD 2000-16-01, the FAA indicated that a supplemental notice of proposed rulemaking (NPRM) was published in the Federal Register on June 12, 2000 (65 FR 36799). After carefulreview of the available data, including the comments received from the public, the FAA determined that air safety and the public interest required the adoption of the rule as proposed in the supplemental NPRM. However, the FAA inadvertently included the requirements from the original NPRM (64 FR 68302, December 7, 1999) in the final rule, rather than the requirements specified in paragraphs (a) and (b) of the supplemental NPRM. The effect of this error is that operators of certain airplanes are not required to accomplish actions that apply to those airplanes, and that certain actions are to be accomplished in accordance with a method approved by the FAA, rather than a specific service bulletin. Therefore, consistent with the FAA's intent in the supplemental NPRM, this correction is necessary to require operators of specific airplanes to replace certain ground block screws with new screws and to reterminate the circuit ground wires of the EPCU to separate grounding points.\n\n\tTheseactions shall be done in accordance with McDonnell Douglas Alert Service Bulletin MD90-24A060, Revision 01, dated September 2, 1999; and McDonnell Douglas Service Bulletin MD90-24-062, dated February 3, 2000; as applicable. The FAA inadvertently omitted McDonnell Douglas Service Bulletin MD90-24-062 from the incorporation by reference paragraph and is incorporating by reference that service bulletin in this final rule.\n\nCorrection of Publication\n\tAction is taken herein to correct these inadvertent errors in AD 2000-16-01 and to correctly add this AD as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13). The AD is reprinted in its entirety for the convenience of affected operators.\n\n\tSince this action only corrects current requirements, it has no adverse economic impact and imposes no additional burden on any person. Therefore, the FAA has determined that notice and public procedures are unnecessary.\n\nList of Subject in 14 CFR Part 39\n\tAir transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.\n\nAdoption of the Correction\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 removing amendment 39-11855 (65 FR 49728, August 15, 2000), and by adding a new airworthiness directive (AD), amendment 39-11915, to read as follows: