65-14-03\tBOEING: Amdt. 39-90 Part 39 Federal Register June 23, 1965. Applies to Models 707 and 720 Series Aircraft Noted in Boeing Service Bulletin No. 2073(R-1). \n\n\tCompliance required as indicated. \n\n\tInvestigation of a recent failure of the nose gear drag brace lock rod upper attachment bolt, which resulted in the affected aircraft landing with the nose gear retracted, indicates that this bolt is susceptible to fatigue failures and requires replacement. \n\n\t(a)\tBolt P/N BAC B30ABP6-37 shall be replaced as follows: \n\n\t\t(1)\tBolts having 5,400 or more hours' time in service on the effective date of this AD shall be replaced in accordance with paragraph (3) within 600 hours' time in service after the effective date of this AD. \n\n\t\t(2)\tBolts having less than 5,400 hours' time in service on the effective date of this AD shall be replaced in accordance with paragraph (3) prior to the accumulation of 6,000 hours' time in service. \n\n\t\t(3)\tReplace nose gear drag brace lock rodupper attachment bolts P/N BAC B30ABP6-37 with a new bolt of the same part number or with Standard Pressed Steel Company bolt SFH 22-6-35, Voi-Shan Mfg. Co. bolt VS 2545H6F35T, or a bolt approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\t\t(4)\tBolts P/N BAC B30ABP6-37 installed in accordance with (3) shall be repetitively replaced thereafter within each 6,000 hours' time in service from the last replacement unless they are replaced with Standard Pressed Steel Co., bolt SFH 22-6-35, Voi-Shan Mfg. Co. bolt VS 2545H6F35T, or a bolt approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\t(b)\tOperators who have not kept records of hours' time in service on nose gear drag brace lock rod upper attachment bolts shall substitute airplane hours' time in service in lieu thereof. \n\n\t(Boeing Service Bulletin No. 2073 (R-1) covers this same subject.) \n\n\tThis directive effective July 23, 1965.