Summary
We propose to adopt a new airworthiness directive (AD) for all Boeing Model 747-100, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400F, and 747SR series airplanes. This proposed AD was prompted by reports of broken and damaged latch pin retention bolts of the main deck side cargo door (MDSCD), latch pin migration, and broken latch pin fittings. This proposed AD would require various repetitive inspections of the MDSCD latch pin fittings, measuring the latch pin, and related investigative and corrective actions if necessary; and modifying the latch pin fittings and installing new latch pins and latch pin fasteners. We are proposing this AD to prevent loss of the cargo door and rapid depressurization of the airplane.