AD 99-21-07 Airworthiness Directives; McDonnell Douglas Model DC-9, DC-9-80, and C-9 (Military) Series Airplanes, and Model MD-88 Airplanes

Models named: MD-88. Read the applicability below — it usually turns on serial or part numbers too.

Model DC-9-81 (MD-81), -82 (MD-82), -83 (MD-83), and 87 (MD-87) series airplanes, and Model MD-88 airplanes; as listed in McDonnell Douglas Service Bulletins MD80-32-276 and MD80- 32-278, both dated March 31, 1995; and Model DC-9-10, -20, -30, -40, and -50; and C-9 (military) series airplanes, as listed in McDonnell Douglas Service Bulletin DC9-32-289, dated March 7, 1996; certificated in any category. Note 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 (h) 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.

Required as indicated, unless accomplished previously. To prevent failure of the hydraulic damper assemblies of the MLG, which could result in vibration damage and collapse of the MLG, accomplish the following: Restatement of Requirements of AD 96-01-09 Modifications (a) For airplanes listed in McDonnell Douglas MD-80 Service Bulletin MD80-32-276, dated March 31, 1995, that have not been previously modified (installation of brake line restrictors) in accordance with McDonnell Douglas MD-80 Service Bulletin MD80-32- 246: Within 9 months after February 26, 1996 (the effective date of AD 96-01-09, amendment 39-9485), install filtered brake line restrictors in the MLG hydraulic brake system in accordance with McDonnell Douglas MD-80 Service Bulletin MD80-32-276, dated March 31, 1995, or Revision 1, dated October 17, 1995. Note 2: Installation of filtered restrictors in accordance with the instructions specified in McDonnell Douglas MD-80 Alert Service Bulletin, MD80-A32-286, dated September 11, 1995, is considered acceptable for compliance with paragraph (a) of this AD. (b) For airplanes listed in McDonnell Douglas MD-80 Service Bulletin MD80-32-278, dated March 31, 1995: Within 36 months after February 26, 1996, modify the hydraulic damper assembly (by removing shims, increasing bolt torque, and incorporating changes to increase the volume of fluid passing between the two damper chambers) in accordance with McDonnell Douglas MD-80 Service Bulletin MD80-32- 278, dated March 31, 1995, or Revision 1, dated September 6, 1995. Restatement of Requirements of AD 96-21-01 Replacement or Modification (c) For airplanes listed in McDonnell Douglas Service Bulletin DC9-32-289, dated March 7, 1996: Within 24 months after November 14, 1996 (the effective date of AD 96-21-01, amendment 39-9777), either replace or modify the MLG hydraulic damper assembly, in accordance with the procedures specified as either ``Option 1'' or ``Option 2,'' respectively, of the service bulletin. New Requirements of this Ad Replacement or Modification (d) For McDonnell Douglas Model DC-9 series airplanes, and C-9 (military) series airplanes (as listed in McDonnell Douglas Alert Service Bulletin DC9-32A311, Revision 01): Within 18 months after the effective date of this AD, accomplish the requirements specified in either paragraph (d)(1) or (d)(2) of this AD in accordance with McDonnell Douglas Service Bulletin DC9-32-311, dated July 6, 1998, or McDonnell Douglas Alert Service Bulletin DC9-32A311, Revision 01, dated March 8, 1999. (1) Modify the left and right MLG hydraulic damper assemblies. (2) Replace the left and right MLG hydraulic damper assemblies with modified and reidentified hydraulic damper assemblies having part number (P/N) SR09320057-7005, SR09320057-7007, SR09320057-7009, or 5923142-5513. (e) For McDonnell Douglas Model DC-9-80 series airplanes, and MD-88 airplanes (as listed in McDonnell Douglas Alert Service Bulletin DC9-32A311, Revision 01): Within 3,000 flight cycles after incorporation of the latest configuration of the left and right MLG hydraulic damper assemblies, or within 9 months after the effective date of this AD, whichever occurs later; accomplish the requirements specified in either paragraph (d)(1) or (d)(2) of this AD in accordance with McDonnell Douglas Service Bulletin DC9-32-311, dated July 6, 1998, or McDonnell Douglas Alert Service Bulletin DC9- 32A311, Revision 01, dated March 8, 1999. (f) Paragraph (b) or (c) of this AD, as applicable, must be accomplished prior to or concurrent with the accomplishment of either paragraph (d) or (e) of this AD, as applicable. Spares (g) As of the effective date of this AD, no person shall install on any airplane a damper sub assembly having P/N SR09320057-9, SR09320057-17, or 5923142-5017; or a damper assembly having P/N SR09320057-7001, SR09320057-7003, or 5923142-5511, unless the part has been modified and reidentified in accordance with paragraph (d)(2) of this AD. Alternative Methods of Compliance (h) 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 [[Page 54517]] 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. Note 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Los Angeles ACO. Special Flight Permits (i) Special 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. Incorporation by Reference (j) The actions shall be done in accordance with McDonnell Douglas MD-80 Service Bulletin MD80-32-276, dated March 31, 1995; McDonnell Douglas MD-80 Service Bulletin MD80-32-276, Revision 1, dated October 17, 1995; McDonnell Douglas MD-80 Service Bulletin MD80-32-278, dated March 31, 1995; McDonnell Douglas MD-80 Service Bulletin MD80-32-278, Revision 1, dated September 6, 1995; McDonnell Douglas Service Bulletin DC9-32-289, dated March 7, 1996; McDonnell Douglas Service Bulletin DC9-32-311, dated July 6, 1998; or McDonnell Douglas Alert Service Bulletin DC9-32A311, Revision 1, dated March 8, 1999; as applicable. (1) The incorporation by reference of McDonnell Douglas Service Bulletin DC9-32-311, dated July 6, 1998; or McDonnell Douglas Alert Service Bulletin DC9-32A311, Revision 1, dated March 8, 1999; is approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. (2) The incorporation by reference of McDonnell Douglas MD-80 Service Bulletin MD80-32-276, dated March 31, 1995, McDonnell Douglas MD-80 Service Bulletin MD80-32-276, Revision 1, dated October 17, 1995; McDonnell Douglas MD-80 Service Bulletin MD80-32- 278, dated March 31, 1995; and McDonnell Douglas MD-80 Service Bulletin MD80-32-278, Revision 1, dated September 6, 1995; was approved previously by the Director of the Federal Register as of February 26, 1996 (61 FR 2407, January 26, 1996). (3) The incorporation by reference of McDonnell Douglas Service Bulletin DC9-32-289, dated March 7, 1996, was approved previously by the Director of the Federal Register as of November 14, 1996 (61 FR 53042, October 10, 1996). (4) Copies may be obtained from Boeing Commercial Aircraft Group, Long Beach Division, 3855 Lakewood Boulevard, Long Beach, California 90846. 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. (k) This amendment becomes effective on November 12, 1999. Issued in Renton, Washington, on September 28, 1999. D.L. Riggin, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 99-25766 Filed 10-6-99; 8:45 am] BILLING CODE 4910-13-U