AD 98-20-08 Airworthiness Directives; McDonnell Douglas Model DC-9-10, -20, - 30, -40, and -50 Series Airplanes and C-9 (Military) Airplanes

Models named: DC-9-10, -20, -30, -40, -50 series. Read the applicability below — it usually turns on serial or part numbers too.

Model DC-9-10, -20, -30, -40, -50 series airplanes, and C-9 (military) airplanes, 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 (f) 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 ensure that fatigue cracking of the frame-to-longeron attachment area and the frame-to-skin shear clips in the aft fuselage is detected and corrected in a timely manner so as to prevent damage to adjacent structure, which could result in loss of the capability of the engine pylon to support engine loads and possible separation of the engine from the airplane, accomplish the following: (a) For airplanes listed in McDonnell Douglas Service Bulletin DC9-53-140, Revision 05, dated February 15, 1996: Perform an eddy current inspection to detect cracking of the longeron-to-frame attachment area and frame-to-skin shear clips of the aft fuselage, in accordance with the Accomplishment Instructions of that service bulletin at the time specified in paragraph (a)(1) or (a)(2) of this AD, as applicable. For airplanes subject to the requirements of paragraph (b) of this AD, the inspection shall be accomplished prior to, or in conjunction with, accomplishment of that paragraph. Thereafter, repeat the inspection at intervals not to exceed 12,500 landings until the modification specified in paragraph (d) of this AD is accomplished. (1) For airplanes that have not been previously inspected using visual inspection techniques in accordance with McDonnell Douglas Corrosion Prevention Control Program (CPCP), Document MDC-K4606, Revision 1, dated December 1990, perform the initial inspection prior to the accumulation of 30,000 total landings, or within 4,000 landings after the effective date of this AD, whichever occurs later. (2) For airplanes that have been previously inspected using visual inspection techniques in accordance with McDonnell Douglas CPCP, perform the initial inspection within 8,500 landings after the previous visual inspection, or within 4,000 landings after the effective date of this AD, whichever occurs later. (b) For airplanes listed in McDonnell Douglas DC-9 Service Bulletin 53-150, [[Page 50490]] Revision 2, dated February 27, 1991: Perform a visual and eddy current inspection to detect cracking of the fuselage bulkhead at the front spar of the engine pylon of the aft fuselage, in accordance with the Accomplishment Instructions of that service bulletin, at the time specified in subparagraph (b)(1) or (b)(2) of this AD, as applicable. Thereafter, repeat the inspection at intervals not to exceed 4,000 landings until the modification specified in the service bulletin (and required by AD 96-10-11) is accomplished. (1) For airplanes that have not been previously inspected using visual inspection techniques in accordance with McDonnell Douglas Corrosion Prevention Control Program (CPCP), Document MDC-K4606, Revision 1, dated December 1990, perform the initial inspection prior to the accumulation of 30,000 total landings, or within 4,000 landings after the effective date of this AD, whichever occurs later. (2) For airplanes that have been previously inspected using visual inspection techniques in accordance with McDonnell Douglas CPCP, perform the initial inspection within 5,000 landings after the previous visual inspection, or within 4,000 landings after the effective date of this AD, which ever occurs later. (c) If any cracking is detected during any inspection required by this AD, prior to further flight, repair the cracking in accordance with either McDonnell Douglas Service Bulletin DC9-53- 140, Revision 05, dated February 15, 1996; or McDonnell Douglas DC-9 Service Bulletin 53-150, Revision 2, dated February 27, 1991; as applicable. (d) For airplanes that are identified in McDonnell Douglas Service Bulletin DC9-53-140, Revision 05, dated February 15, 1996, but are not identified in Revision 3 of that service bulletin: Prior to the accumulation of 86,000 total landings, or within 4 years after the effective date of this AD, whichever occurs later, modify the longeron-to-frame attachment area and frame-to-skin shear clips, in accordance with McDonnell Douglas Service Bulletin DC9-53-140, Revision 05, dated February 15, 1996. Accomplishment of this modification constitutes terminating action for the repetitive inspection requirements of paragraph (a) of this AD. Note 2: Airplanes identified in Revision 3 of McDonnell Douglas Service Bulletin DC9-53-140 are required to accomplish the modification specified in paragraph (d) of this AD in accordance with the requirements of AD 96-10-11. (e) Accomplishment of the inspection requirements of this AD constitutes terminating action for the corresponding inspection requirements of AD 96-10-11 (which are required to be accomplished in accordance with McDonnell Douglas Service Bulletin DC9-53-140, Revision 3, dated March 12, 1986, and McDonnell Douglas DC-9 Service Bulletin 53-150, Revision 2, dated February 27, 1991). (f) 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, 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. (g) 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. (h) The actions shall be accomplished in accordance with McDonnell Douglas Service Bulletin DC9-53-140, Revision 05, dated February 15, 1996; and McDonnell Douglas DC-9 Service Bulletin 53- 150, Revision 2, dated February 27, 1991, as applicable. 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, Department 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. (i) This amendment becomes effective on October 27, 1998. Issued in Renton, Washington, on September 14, 1998. Dorenda D. Baker, Acting Manager, Transport Airplane Directorate, Aircraft Certification Service. [FR Doc. 98-25030 Filed 9-21-98; 8:45 am] BILLING CODE 4910-13-P