Airworthiness Directives; Airbus Model A310 and A300-600 Series Airplanes

This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) T96-01-52 that was sent previously to all known U.S. owners and operators of Airbus Model A310 and A300-600 series airplanes by individual telegrams. Among other things, this AD requires repetitive inspections to ensure correct synchronization of the hydraulic control valves of the trimmable horizontal stabilizer (THS) actuator; replacement of the horizontal stabilizer actuator motors with new or serviceable motors and resynchronization of the valves, or adjustment of the synchronization, if necessary; and a functional test of the THS. This amendment is prompted by a report of desynchronization of the hydraulic control valves that direct fluid to the horizontal stabilizer actuator motors, which resulted in uncommanded movement of the THS. The actions specified by this AD are intended to prevent such desynchronization, which could lead to runaway of the horizontal stabilizer to its full up or down position, subsequent reduced maneuvering capability, and potential pitch upset.