Summary
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to all Airbus Model A318-100 and A319-100 series airplanes, Model A320-111 airplanes, and Model A320-200, A321-100, and A321-200 series airplanes. The existing AD currently requires repetitive inspections of the upper and lower attachments of the trimmable horizontal stabilizer actuator (THSA) to measure for proper clearance and to detect cracks, damage, and metallic particles. The existing AD also requires corrective actions, if necessary, and reports of inspection findings. This proposed AD would shorten the repetitive interval for inspecting the upper THSA attachment. This proposed AD results from new test results on the secondary load path, which indicated the need to shorten the repetitive interval for inspecting the upper THSA attachment. We are proposing this AD to detect and correct failure of the THSA's primary load path, which could result in latent (undetected) loading and eventual failure of the THSA's secondary load path and consequent uncontrolled movement of the horizontal stabilizer and loss of control of the airplane.