Airworthiness Directives; Airbus Model A330, A340-200, and A340-300 Series Airplanes

This amendment supersedes an existing airworthiness directive (AD), applicable to the airplane models listed above. That AD currently requires repetitive inspections to detect discrepancies of the transfer tubes and the collar of the ball nut of the trimmable horizontal stabilizer actuator (THSA), and corrective action if necessary. This amendment expands the applicability of the existing AD; and requires new repetitive inspections for discrepancies of the ball screw assembly; corrective action if necessary; repetitive greasing of the THSA ball nut, and replacement of the THSA if necessary; and a modification or replacement (as applicable) of the ball nut assembly, which would end certain repetitive inspections. The actions specified by this AD are intended to prevent degraded operation of the THSA due to the entrance of water into the ball nut. Degraded operation could lead to reduced controllability of the airplane. This action is intended to address the identified unsafe condition.