AD 2005-07-04 required 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; repetitive inspections for discrepancies of the ball screw assembly, and corrective action if necessary; repetitive greasing of the THSA ball nut, and replacement of the THSA if necessary; and modification or replacement (as applicable) of the ball nut assembly, which ends certain repetitive inspections.
This new AD removes certain inspections, revises certain actions, and adds airplanes to the applicability. This AD was prompted by several reports of disconnection of the transfer tube from the ball nut of the THSA. We are issuing this AD to prevent degraded operation of the THSA, which could result in reduced controllability of the airplane.
This AD becomes effective September 10, 2013.