Airworthiness Directives; Boeing Model 747-100 and -200 Series Airplanes Modified in Accordance With Supplemental Type Certificate (STC) SA2322SO or SA4227NM-D.

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) T96-01-51 that was sent previously to all known U.S. owners and operators of certain Boeing Model 747-100 and -200 airplanes by individual telegrams. This AD requires repetitive inspections of the latch safety pins of the main deck side cargo door to ensure that the door is securely latched and locked; it also requires deactivation of certain panel lights and installation of a placard to indicate such deactivation. This amendment is prompted by a report of a malfunction of the safety interlock system of the main deck side cargo door on one airplane. The actions specified by this AD are intended to prevent such malfunctions, which could result in the opening of the main deck side cargo door while the airplane is in flight, and subsequent rapid decompression of the airplane.