Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Boeing Model 747-200C and 747-200F series airplanes. This proposed AD would require repetitive inspections for cracking of the left and right C-3 frame upper closure fittings of the nose cargo door, and corrective actions if necessary. This proposed AD also provides an optional modification that, if done, would terminate inspections in certain areas. This proposed AD is prompted by reports indicating that fatigue cracking was found in the inboard flange above the flight deck floor on the C-3 frame upper closure fittings of the nose cargo door. We are proposing this AD to detect and correct cracking of the C-3 frame upper closure fittings, which could extend and result in rapid depressurization of the airplane.