Summary
This document proposes the supersedure of an existing airworthiness directive (AD), applicable to certain Airbus Model A330 and A340 series airplanes, that currently requires repetitive operational tests of the override mechanism of the trimmable horizontal stabilizer (THS) to determine if the system functions correctly; and corrective action, if necessary. This action would require replacement of existing flight control primary computers (FCPC) with improved FCPC's, which would terminate the repetitive operational tests. This proposal is prompted by the issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this proposal are intended to prevent uncommanded movement of the THS, which could result in reduced controllability of the airplane.