Airworthiness Directives; Airbus Model A330-301, -321, and -322 Series Airplanes; and Model A340-211, -212, -213, -311, -312, and -313 Series Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to all Airbus Model A330-301, -321, and -322 series airplanes; and Model A340-211, -212, -213, -311, -312, and -313 series airplanes. The existing AD requires repetitive replacements of the yaw damper actuator installed on active position with a new or overhauled actuator. This action adds a requirement, for certain airplanes, to install upgraded flight control primary computers, which terminates the requirement for the repetitive actuator replacements for those airplanes. This action is necessary 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 the complete loss of the green hydraulic circuit, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.