Summary
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to all Airbus Model A330-301, -321, and -322 series airplanes, and Model A340-211, -212, -213, -311, -312, and -313 series airplanes. This proposal would require repetitive replacements of the yaw damper actuator installed on active position with a new or overhauled yaw damper actuator. This proposal is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by the proposed AD are intended to prevent hydraulic leakage from the yaw damper actuator installed on active position due to premature wear of the dynamic seals between the actuator piston and the piston bearing. Hydraulic leakage could lead to complete loss of the green hydraulic circuit, which could result in reduced controllability of the airplane.