64-19-01\tBOEING: Amdt. 787 Part 507 Federal Register August 7, 1964. Applies to Models 707 and 720 Series Aircraft. \n\n\tCompliance required as indicated. \n\n\tAs a result of several incidents involving loss of air conditioning bay access doors, accomplish the following:\n \n\t(a)\tWithin 550 hours' time in service after the effective date of this AD, unless accomplished within the last 2,500 hours' time in service, and at intervals thereafter not to exceed 3,050 hours' time in service from the last inspection: \n\n\t\t(1)\tOn all Models 707 and 720 Series aircraft, inspect for lobe wear the five hinges on the left and right-hand air conditioning bay access doors and the mating hinges located on the bottom of the fuselage between fuselage Station 620 and 820.\n \n\t\t(2)\tRemove any hinges that have lobe wall thicknesses less than 0.030 inches and replace with new hinges of the same part number or an FAA approved equivalent hinge, before further flight.\n \n\t\t(3)\tOn aircraft Serial Numbers17586 through 17619, 17623 through 17626, 17628 through 17652, 17658 through 17673, 17675 through 17684, 17692 through 17706, 17718 through 17720, 17722 through 17724, 17903 through 17905, 17907 through 17909, 17925 through 17927 and 18013, visually inspect the air conditioning bay access doorframes and the hinges thereon for cracks around the rivets attaching the hinges to the door. Before further flight, replace cracked hinges with hinges of the same part number or an FAA-approved hinge, and if the doorframes are cracked, either replace the doors with new doors or repair them in accordance with the applicable Boeing Structural Repair Manual, or repair data approved by a Boeing Structural Designated Engineering Representative (DER). \n\n\t(b)\tThe inspections specified in (a)(3) may be discontinued when reinforcement plates and bolts are added to the access doors in accordance with Paragraph 3, Modification Data, of Boeing Service Bulletin No. 879, dated July 8, 1960, or an FAA Western Region, Aircraft Engineering Division, approved equivalent. \n\n\t(c)\tUpon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Aircraft Engineering Division, FAA Western Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase for such operator. \n\n\t(Boeing Service Bulletin No. 879 pertains to this same subject.) \n\n\tThis directive effective September 7, 1964.