73-14-01: Main Cargo Door Latch Support Fittings

73-14-01 BOEING: Amdt. 39-1682. Applies to all Model 707 airplanes manufactured prior to December 1, 1967, with non-shot peened 7079-T6 main deck cargo door latch support fittings. \n\tCompliance required as indicated. \n\t(a)\tWithin the next 1500 hours' time in service after the effective date of this AD and at intervals thereafter not to exceed 1500 hours' time in service, inspect the main deck cargo door latch support fittings per (b) below. Airplanes with a cracked fitting may be operated in accordance with paragraph (d) or (e) below or the cracked fitting may be replaced in accordance with paragraph (c). \n\t(b)\tInspect in accordance with Boeing Alert Service Bulletin 3124, dated January 29, 1973, or later FAA approved revisions, or in a manner approved by the Chief, Engineering and Manufacturing Branch, F.A.A., Northwest Region, for cracks emanating from the barrel nut hole on each of the eight fittings using visual, or dye penetrant, or eddy current methods. \n\t(c)\tIf cracks are found emanating from the barrel nut hole, replace with a shot-peened 7079-T6 fitting; or replace with a 7075-T73 fitting; or repair in a manner approved by the Chief, Engineering and Manufacturing Branch, F.A.A., Northwest Region, prior to further flight. \n\t(d)\tIf cracks are found emanating from the barrel nut hole on any one of the two most forward or two most aft fittings, the airplane may be continued in service if flown unpressurized and the inspections per (f) are accomplished. \n\t(e)\tAirplanes with not more than one of the four center fittings cracked at the barrel nut hole, may be continued in service at a reduced cabin operating pressure, of not more than 6.0 psi cabin pressure differential, provided the inspections per (f) are accomplished. \n\t(f)\tWhen required by (d) or (e) all fittings must be re-inspected at intervals not to exceed 200 hours' time in service in accordance with (b) above. If crack growth occurs or if additional fittings are found cracked at the barrel nuthole, replace the cracked fittings prior to further flight. \n\t(g)\tThe installation of either shot peened 7079-T6 fittings or 7075-T73 fittings is terminating action for this AD. \n\t(h)\tUpon request of the operator, a FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA, Northwest Region, may adjust the repetitive inspection intervals if the request contains substantiating data to justify the increase. \n\t(i)\tAircraft having fittings which require rework under this AD may be flown unpressurized in accordance with FAR 21.197, to a base where rework can be accomplished. \n\tThis AD, Amendment 39-1682, supersedes AD 73-4-1. \n\tThis Amendment 39-1682 becomes effective upon date of publication.