Summary
The FAA is revising an earlier NPRM for an airworthiness directive (AD) that applies to all Airbus Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model C4-605R Variant F airplanes (collectively called A300-600 series airplanes); and A310-200 and -300 series airplanes. The original NPRM would have required a one-time inspection of the trimmable horizontal stabilizer actuator (THSA), corrective actions if necessary, and follow-on repetitive tasks. The original NPRM resulted from reports of THSAs that have reached their design operational life. This operational life can be extended provided an initial inspection and follow-on repetitive tasks are accomplished. This action revises the original NPRM by revising the initial compliance time. It also allows the component maintenance manual as an alternative repair method. We are proposing this supplemental NPRM to extend the operational life of the THSA to prevent a possible failure of high-time THSAs, which could result in reduced controllability of the airplane.