89-08-03 R1 BOEING: Amendment 39-6183 as revised by Amendment 39-6389. Docket No. 89-NM-104-AD. \n\n\tApplicability: Model 747 series airplanes, listed in Boeing Service Bulletin 747-53-2297, dated June 30, 1988, certificated in any category, except line number 001 through 065. \n\tCompliance: Required as indicated, unless previously accomplished. \n\n\tTo prevent depressurization as a result of failure of the crease beam and resultant adjacent frame failure, accomplish the following: \n\n\tA.\tFor airplanes not modified in accordance with Boeing Service Bulletin 747-53-2297, dated June 30, 1988, or Boeing Service Bulletin 747-53-2244, dated September 20, 1985. \n\n\t\t1.\tPerform detailed visual and dye penetrant inspections of the body crown crease beam for cracks, from BS 940 to BS 1000 and from stringers S-8L to S-8R, at the times specified in the table below, in accordance with Boeing Service Bulletin 747-53-2297, dated June 30, 1988. In addition, perform a detailed visual inspection for cracks in all adjacent intercostals, skins (internal and external), and stringers in the same area, in accordance with Boeing Service Bulletin 747-53-2297, dated June 30, 1988. \n\n\t\n\nFor Unmodified Airplanes: \n\nAccumulated landings as of effective date of AD\nInitial Compliance Period for Paragraph A. of this AD\n13,000 or more\t\nWithin 1,000 landings after the effective date of this AD.\nBetween 7,500 and 13,000\nWithin 2,500 landings after the effective date of this AD, but not to exceed 14,000 total landings on the airplane. \n7,500 or less\nPrior to accumulation of 10,000 landings. \n\n\t\t2.\tIf no cracks are found, repeat the detailed visual and penetrant inspections required by paragraph A.1., above, at intervals not to exceed 6,000 landings. \n\n\t\t3.\tIf cracks are found, repair in accordance with Boeing Service Bulletin 747-53-2297, dated June 30, 1988, prior to further flight, except as noted in paragraph A.4, below. \n\n\t\t4.\tRepair of cracks less than 1.5 inches:If there are no more than three cracks in the web and no more than three cracks in any one flange of the outer tee chord, repair of the crease beam crack may be deferred for up to 1,500 landings by stop-drilling crack ends in accordance with Boeing Service Bulletin 747-53-2297, dated June 30, 1988, and repeating the detailed visual and penetrant inspection required by paragraph A.1., above, at intervals not to exceed 250 landings until repair in accordance with paragraph A.3., above, is accomplished. \n\n\t\t5.\tPrior to the accumulation of 6,000 landings after a repair and thereafter at intervals not to exceed 6,000 landings, perform the detailed visual and penetrant inspections for cracks required by paragraph A., above, including any crease beam area where cracks were found. Before further flight, repair any additional cracks found, in accordance with a method approved by the Manager, Seattle Aircraft Certification Office, FAA, Northwest Mountain Region. \n\n\tB.\tFor airplanes thathave been modified in accordance with Boeing Service Bulletin 747-53-2297, dated June 30, 1988, or Boeing Service Bulletin 747-53-2244, dated September 20, 1985: Prior to the accumulation of 10,000 landings after the modification, or within the next 500 landings after the effective date of this AD, whichever occurs later, and thereafter at intervals not to exceed 6,000 landings, perform the body crown crease beam detailed visual and penetrant inspections for cracks as required by paragraph A., above. If cracks are found, prior to further flight, repair in accordance with Boeing Service Bulletin 747-53-2297, dated June 30, 1988. \n\n\tC.\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: The request should be forwarded through an FAA Principal Maintenance Inspector (PMI), who may add any commentsand then send it to the Manager, Seattle Aircraft Certification Office. \n\n\tD.\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, 9010 East Marginal Way South, Seattle, Washington. \n\n\tThis AD revises AD 89-08-03 (Amendment 39-6183) which became effective on May 8, 1989. \n\n\tThis amendment (39-6389, AD 89-08-03 R1) becomes effective on November 3, 1989.