Airworthiness Directives; Boeing Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747SR, and 747SP Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing airplane models, that requires a one-time inspection to identify all H-11 steel bolts installed in the latch fittings of the cargo doors, repetitive inspections for cracked or broken H-11 steel bolts, and follow-on and corrective actions if necessary. This amendment also requires eventual replacement of all H- 11 steel bolts in the latch fittings of the cargo doors with Inconel bolts. This action is necessary to prevent broken bolts in the latch fittings, which could reduce the capability of the door latch to keep the door closed, and result in loss of a cargo door and consequent rapid depressurization of the airplane. This action is intended to address the identified unsafe condition.