88-24-08 R2 MCDONNELL DOUGLAS: Amendment 39-6071, as revised by Amendment 39-6108, is further revised by Amendment 39-6469. Docket No. 89-NM-41-AD. \n\n\tApplicability: Model DC-9-10, -20, -30, -40, -50, and C-9 (Military) series airplanes, certificated in any category. \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tTo prevent fatigue cracking and subsequent failure of the fuselage skin or longerons, accomplish the following: \n\n\tA.\tPrior to the accumulation of 45,000 landings, or within 30 days after January 28, 1989, (the effective date of Amendment 39-6108), whichever occurs later, unless accomplished within the last 2,500 landings, perform initial external low and high frequency eddy current inspections of the fuselage skin and longerons from longeron 7 left through 7 right, in accordance with the accomplishment instructions of McDonnell Douglas DC-9 Alert Service Bulletin A53-230, Revision 3, dated September 28, 1989, within the range of fuselage stations for the particular series airplanes as specified in Table 1 of that service bulletin. \n\n\tNOTE: Inspections performed in accordance with McDonnell Douglas DC-9 Alert Service Bulletin A53-230, N/C, dated November 2, 1988, Revision 1, dated December 22, 1988, or Revision 2, dated April 21, 1989, meet the requirements of this paragraph. \n\n\tB.\tPrior to the accumulation of 30,000 landings, or within 90 days after the effective date of this amendment, whichever occurs later, unless accomplished within the last 2,500 landings, perform initial external low and high frequency eddy current inspections of the fuselage skin and longerons from longeron 7 left through 7 right, in accordance with the accomplishment instructions of McDonnell Douglas DC-9 Alert Service Bulletin A53-230, Revision 3, dated September 28, 1989, within the range of fuselage stations for the particular series airplanes as specified in Table 1 of that Service Bulletin. \n\n\tNOTE: Inspections performed in accordance with McDonnell Douglas DC-9 Alert Service Bulletin A53-230, N/C, dated November 2, 1988; Revision 1, dated December 22, 1988; or Revision 2, dated April 21, 1989; meet the requirements of this paragraph. \n\n\tC.\tPrior to the accumulation of 2,500 landings after the accomplishment of the external inspections in accordance with paragraph A. or B., above, perform an aided visual inspection of the longerons from longeron 10 left through 10 right from inside the fuselage, in accordance with the accomplishment instructions of McDonnell Douglas DC-9 Alert Service Bulletin A53-230, Revision 3, dated September 28, 1989, within the range of fuselage stations for the particular series airplanes as specified in Table 2 of that Service Bulletin. \n\n\tD.\tAs an option to the initial visual inspection required by paragraph C., above, for airplanes that have previously accomplished an internal visual inspection of only longerons 7 left through 7 right prior to the effective date of this amendment: Prior to the accumulation of 2,500 landings after that internal visual inspection, perform an external high frequency eddy current inspection of longerons 8 left through 10 left, and 8 right through 10 right, within the range of fuselage stations for the particular series airplanes, as specified in Table 2 of McDonnell Douglas DC-9 Alert Service Bulletin A53-230, Revision 3, dated September 28, 1989. Repeat this external eddy current inspection at intervals not to exceed 2,500 landings until the internal visual inspection (of longerons 10 left through 10 right) required by paragraph C., above, is accomplished prior to the accumulation of 7,500 landings after the effective date of this amendment. \n\n\tE.\tExcept as provided by paragraph D., above, conduct repetitive inspections according to either paragraph E.1. or E.2., below: \n\n\t\t1.\tRepeat the external eddy current and internal visual inspections as required by paragraphs A., or B., and C., above, at intervals not to exceed 5,800 landings: or \n\n\t\t2.\tRepeat the external eddy current inspections as required by paragraph A. or B., above, from longerons 10 left through 10 right at intervals not to exceed 2,500 landings. \n\n\tF.\tIf cracks are detected prior to further flight, repair in accordance with McDonnell Douglas DC-9 Alert Service Bulletin A53-230, Revision 3, dated September 28, 1989. If Option II, Condition 2, of the Service Bulletin is selected, accomplish removal of interim repair doubler(s) and accomplish permanent longeron repair(s) within 2,500 landings after installation of the interim repair doublers. \n\n\tG.\tCompletion of the rework procedure defined in McDonnell Douglas Service Rework Drawing SR09530132, Revision B, dated July 28, 1989, constitutes terminating action for the repetitive inspection requirements of this AD. \n\n\tH.\tAn alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tNOTE: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment and then send it to the Manager, Los Angeles Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tI.\tSpecial flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD. \n\n\tAll persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to McDonnell Douglas Corporation, 3855 Lakewood Boulevard, Long Beach, California 90846, Attention: Business Unit Manager of Publications, CI-HCO (54-60). These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or the Los Angeles Aircraft Certification Office, 3229East Spring Street, Long Beach, California. \n\n\tThis AD revises AD 88-24-08 R1 (Amendment 39-6108) which revised AD 88-24-08 (Amendment 39-6071). \n\n\tThis amendment (39-6469, AD 88-24-08 R2) becomes effective on February 12, 1990.