64-04-02 BOEING: Amdt. 687 Part 507 Federal Register February 20, 1964. Applies to All Airplanes Listed in Boeing Service Bulletin No. 942 On Which Service Bulletin No. 942 Has Not Been Accomplished. \n\n\tCompliance required at the next terminal where adequate facilities and personnel are available but not to exceed 30 hours' time in service after the effective date of this AD, unless already accomplished in accordance with Boeing Alert Service Bulletin No. 1967 dated January 31, 1964. \n\n\tInspect both stabilizer center section rear spar upper attach fittings visually for cracks. Inspect all visible areas of the lug area (left and right side). Use a mirror to inspect outboard edge of lug that is sandwiched between lugs of mating part. Replace any center section having cracked parts before further flight.\n \n\tThis directive effective upon publication in the Federal Register for all persons except those to whom it was made effective immediately by telegram dated February 4, 1964.