AD FAA-2012-0299

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