Airworthiness Directives; Airbus Airplanes

We are adopting a new airworthiness directive (AD) for all Airbus Model A318, A319, A320, and A321 series airplanes. This AD was prompted by reports of wear of the trimmable horizontal stabilizer actuator (THSA). This AD requires repetitive inspections of the THSA for damage, and replacement if necessary; and replacement of the THSA after reaching a certain life limit. We are issuing this AD to detect and correct wear on the THSA, which would reduce the remaining life of the THSA, possibly resulting in premature failure and consequent reduced control of the airplane.