65-06-03\tBOEING: Amdt 39-49 Part 39 Federal Register March 17, 1965. Applies to Models 707 and 720 Aircraft with the Serial Numbers Listed in Boeing Service Bulletin No. 2029. \n\tCompliance required as indicated. \n\tCracks have recently been discovered on two airplanes in the aft elevator control quadrant, P/N 50-3119, around the upper two bolts, P/N NAS 1105, which attach the quadrant to the elevator control torque tube. In both instances, Boeing Service Bulletin No. 1259 had not been accomplished, and an interference fit existed between the quadrant and torque tube. As a result of these cracks, the following or an equivalent approved by the Aircraft Engineering Division, FAA Western Region, shall be accomplished: \n\t(a)\tWithin the next 600 hours' time in service after the effective date of this AD, unless already accomplished within the last 600 hours' time in service, and thereafter at periods not to exceed 1,200 hours' time in service from the last inspection, inspect by eddy current or fluorescent dye penetrant the aft elevator quadrant, P/N 50-3119, in accordance with paragraph 3.c. of Service Bulletin No. 2029 or later FAA-approved revisions for evidence of cracks in the upper hub and in the vicinity of the two upper bolts which attach the quadrant to the elevator control torque tube. \n\t(b)\tIf a crack is found, replace the elevator control quadrant with one of the same part number before further flight. The inspections in (a) also apply to the replacement part. \n\t(c)\tWithin the next 6,000 hours' time in service after the effective date of this AD, accomplish rework and dimensional checks in accordance with paragraph 3 of Boeing Service Bulletin 2029 or later FAA-approved revisions. \n\t(d)\tWhen the rework and dimensional checks required by (c) are accomplished, the repetitive inspections specified in (a) may be discontinued. \n\t(e)\tUpon request of an 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\t(Boeing Service Bulletin No. 2029 covers this same subject.) \n\tThis directive effective April 16, 1965.