70-26-03 BOEING: Amdt. 39-1130 as amended by Amendment 39-1161 is further amended by Amendment 39-1307. Applies to all Model 727 series airplanes. \n\n\tCompliance required on all airplanes with 10,000 or more landings as follows: \n\n\t(1)\tWithin 300 landings after the effective date of this AD where not previously inspected in accordance with these procedures; or \n\t(2)\tWithin 2000 landings since the initial inspection where previously inspected in accordance with these procedures; and \n\t(3)\tThereafter at intervals not to exceed 2000 landings since the last such inspection. \n\tTo detect cracks in the main landing gear trunnion support beam, P/N 65-16230, accomplish the following: \n\n\t(a)\tInspect in accordance with Boeing Service Bulletin 57-115, dated November 20, 1970, or later FAA approved revisions, or an equivalent inspection approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\t(b)\tIf cracks are found, before further flight, accomplish one of the following: \n\t\t(1)\tRework the beam in accordance with rework instructions in Boeing Service Bulletin 57-120, dated 30 April 1971, or later FAA approved revisions, and repeat the inspection required in (3) above, or \n\t\t(2)\tRepair the beam in a manner approved by the Chief, Aircraft Engineering Division, FAA Western Region, and repeat the inspection required in (3) above, or \n\t\t(3)\tReplace the beam with a serviceable beam. If this beam is a previously reworked beam, or has 10,000 or more landings, repeat the inspection required in (3) above. \n\t(c)\tWhere records maintained by the operator are such as will permit a clear determination of the number of landings accumulated by the main landing gear trunnion support beam, P/N 65-16230, installed on the airplane, the inspection times prescribed by this AD may be applied to the beam rather than to the airplane. \n\t(d)\tInspections prescribed by this AD do not apply. \n\t\t(1)\tTo replacement beams P/N 65-62335; or \n\t\t(2)\tTo replacement beams P/N65-16230 until the replacement beams (P/N 65- 16230) have accumulated 10,000 landings. \n\tFor the purpose of this AD the number of landings may be determined by dividing each airplane's hours' time in service by the operator's fleet average time from takeoff to landing for the airplane type. \n\tAmendment 39-1130 became effective December 30, 1970. \n\tAmendment 39-1161 became effective March 6, 1971. \n\tThis amendment 39-1307 becomes effective October 8, 1971.