Summary
The Federal Aviation Administration (FAA) proposes to adopt a new airworthiness directive (AD) that is applicable to General Electric Company (GE) CF6-80A1/A3 and CF6-80C2A PMC series turbofan engines. This proposal would require performing either a Directional Pilot Valve (DPV) pressure switch moisture purge procedure and an operational check of the fan reverser or replacing the DPV assembly with a serviceable assembly and performing an operational check of the fan reverser. Thereafter, this AD would require one of these actions on a repetitive basis. This proposal is prompted by a review of fan reverser safety analyses resulting from the discovery of an undetectable failure mode of the DPV pressure switch on certain GE CF6-80C2A and CF6-80A engine models. The actions specified in the proposed AD are intended to prevent inadvertent fan reverser deployment, which, if it occurred in-flight, could result in loss of control of the airplane.