89-11-06 R1 BOEING: Amendment 39-6219 as corrected by Amendment 39-6515. Docket No. 88-NM-117-AD. \n\n\tApplicability: Model 737 series airplanes, listed in Boeing Alert Service Bulletin 737- 53A1027, Revision 3, dated December 2, 1983, certificated in any category. \n\n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tTo prevent failure of the forward lower cargo compartment frames, accomplish the following: \n\n\tA.\tExcept as provided by paragraph B., below, accomplish one of the following prior to the accumulation of 29,000 total landings or within the next 100 landings after June 22, 1989 (the effective date of Amendment 39-6219), whichever occurs later: \n\n\t\t1.\ta.\tUnless previously accomplished within the last 200 landings, conduct a close external visual inspection of the fuselage skin for cracks in the region of the frames specified by Boeing Service Bulletin 737-53A1027, Revision 3, dated December 2, 1983. Reinspect at intervals not to exceed 300 landings until the frames are inspected in accordance with paragraph A.1.b., below. If cracks are found, prior to further flight, repair fuselage skin in accordance with an FAA-approved method and visually inspect the fuselage frames specified by the aforementioned service bulletin for cracks. Frames found cracked must be repaired prior to further flight, in accordance with the service bulletin. \n\n\t\t\tb.\tPrior to the accumulation of 31,400 total landings, or within 100 landings after June 22, 1989 (the effective date of Amendment 39-6219), whichever occurs later, unless previously accomplished within the last 6,600 landings, and thereafter at intervals not to exceed 9,000 landings, conduct a visual inspection for cracks of the fuselage frames specified in paragraph A.1.a., above. If cracks are found, repair fuselage frames, prior to further flight, in accordance with Boeing Alert Service Bulletin 737-53A1027, Revision 3, dated December 2, 1983. \n\n\t\t2.\tUnless previously accomplishedwithin the last 1,900 landings, conduct an x- ray inspection for cracks of the fuselage frames specified in paragraph A.1.a., above, in accordance with procedures described in the Boeing Model 737 Nondestructive Test Manual D6- 37239, Part 2, Subject 53-10-16. Reinspect at intervals not to exceed 2,000 landings. If cracks are found, repair fuselage frames prior to further flight, in accordance with Boeing Alert Service Bulletin 737-53A1027, Revision 3, dated December 2, 1983. \n\n\t\t3.\tUnless previously accomplished within the last 8,900 landings, perform an internal visual inspection for cracks of the fuselage frames specified in paragraph A.1.a., above. Reinspect at intervals not to exceed 9,000 landings. If cracks are found, repair fuselage frames prior to further flight, in accordance with Boeing Alert Service Bulletin 737-53A1027, Revision 3, dated December 2, 1983. \n\n\t\t4.\tUnless previously accomplished within the last 8,900 landings, conduct a low frequency eddy current inspection for cracks of the fuselage frames specified in paragraph A.1.a., above, in accordance with procedures described in Boeing Model 737 Nondestructive Test Manual D6-37239, Part 6, Subject 53-10-01. Reinspect at intervals not to exceed 9,000 landings. If cracks are found, repair fuselage frames prior to further flight, in accordance with Boeing Alert Service Bulletin 737-53A1027, Revision 3, dated December 2, 1983. \n\n\tB.\tFor those airplanes that have been modified in accordance with Part III of Boeing Alert Service Bulletin 737-53A1027, Revision 3, dated December 2, 1983, or the terminating modification described in AD 81-13-08: Prior to the accumulation of 15,600 landings after modification or within the next 1,000 landings after June 22, 1989, (the effective date of Amendment 39-6219), whichever occurs later, perform the inspection described in paragraph A.3., above, and repeat thereafter at intervals not to exceed 15,600 landings. As an alternate to this repetitive inspection, the external inspection described in paragraph A.1.a., above, may be performed at intervals not to exceed 6,600 landings. If cracks are found, repair fuselage skins and frames prior to further flight, in accordance with Boeing Alert Service Bulletin 737- 53A1027, Revision 3, dated December 2, 1983, or in a manner approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. These repairs do not constitute terminating action and are subject to the repetitive inspection requirements of this paragraph. \n\n\tC.\tFor the purposes of complying with this AD, the number of landings may be determined to equal the number of pressurization cycles where the cabin pressure differential was greater than 2.0 PSI. \n\n\tD.\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, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tNOTE: Therequest should be forwarded through an FAA Principal Maintenance Inspector (PMI), who will either concur or comment and then send it to the Manager, Seattle Aircraft Certification Office. \n\n\tNOTE: Inspection and modification in accordance with Boeing Alert Service Bulletin 737-53A1027, Revision 4, dated July 13, 1984; Revision 5, dated February 1, 1985; and Revision 6, dated August 25, 1988; are acceptable alternate means of compliance for this AD. \n\n\tE.\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 Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 17900 Pacific Highway South, Seattle, Washington, or the Seattle Aircraft Certification Office, FAA, Northwest Mountain Region, 9010 East Marginal Way South, Seattle, Washington. \n\n\tAirworthiness Directive 89-11-06 superseded AD 81-13-08, Amendment 39-4141, which became effective on July 1, 1981. \n\tThe effective date of the requirements of this amendment remains June 22, 1989, as specified in Amendment 39-6219. \n\tThis correction (Amendment 39-6515, AD 89-11-06 R1) becomes effective on February 21, 1990.