Summary
The FAA proposes to supersede an existing airworthiness directive (AD) that applies to Airbus Model A300 B2 and B4 series airplanes equipped with General Electric CF6-50 engines. The existing AD currently requires deactivating both thrust reversers and revising the airplane flight manual (AFM) to require performance penalties during certain takeoff conditions to ensure that safe and appropriate performance is achieved for airplanes on which both thrust reversers have been deactivated. This proposed AD would require one-time inspections of the directional pilot valve (DPV), the rocker arm and associated hardware, and corrective actions if necessary; reactivation of both thrust reversers; and repetitive inspections of the DPV and the associated control mechanism of the thrust reversers for incorrect assembly or excessive wear, and corrective actions if necessary. Accomplishing all of the proposed actions would allow the removal of the AFM limitations in the existing AD. This proposed AD results from reports indicating that the DPV was assembled incorrectly; further investigation revealed excessive wear on certain correctly assembled DPVs and the associated control mechanism. We are proposing this AD to prevent uncommanded in-flight deployment of a thrust reverser, which could result in reduced controllability of the airplane.