AD FAA-2017-0498

We are superseding Airworthiness Directive (AD) 2015-15-10, which applied to all Airbus Model A318, A319, A320, and A321 series airplanes. AD 2015-15-10 required repetitive inspections of the trimmable horizontal stabilizer actuator (THSA) for damage, and replacement if necessary; and replacement of the THSA after reaching a certain life limit. This AD requires repetitive detailed inspections of certain THSAs, and related investigative and corrective actions if necessary. This AD was prompted by the establishment of an additional life limit for the THSA, based on flight cycles. In addition, the THSA manufacturer has issued service information which, when accomplished, increases the life limit of the THSA. We are issuing this AD to address the unsafe condition on these products.