Airworthiness Directives; The Boeing Company Airplanes

We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model and 777 airplanes. This AD was prompted by reports of uncommanded door closure of a large lower lobe cargo door. This AD requires inspecting for part numbers and serial numbers of the rotary actuators of the forward and aft large lower lobe cargo doors, as applicable, and corrective action if necessary. We are issuing this AD to detect and correct rotary actuators made with a material having poor actuator gear wear characteristics, which could result in failure of the rotary actuators for the forward or aft large lower lobe cargo doors and subsequent uncommanded door closure, which could possibly result in fatal injury to people on the ground.