Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Airbus Model A300-600 series airplanes. This proposal would require repetitive replacement of the universal joints and steady bearings of the flap transmission system with new parts at regular intervals. This proposal is prompted by a report of a malfunction of a universal joint in the flap transmission system on one wing due to fatigue failure. The actions specified by the proposed AD are intended to ensure replacement of universal joints and bearings of the transmission system when they have reached their maximum life limit; failure of universal joints and bearings could lead to an asymmetric condition of the flaps, which could adversely affect controllability of the airplane.