FAA Proposes Airworthiness Directive for Citation X APU

The FAA proposes an airworthiness directive for the Cessna 750 Citation X prompted by reports of direct current (DC) generator overvoltage events. The generator control unit (GCU) overvoltage protection circuit can become damaged and allow high voltage to pass through to the airplane systems and electrical components, which, if not corrected, could result in smoke in the cockpit and loss of avionics and electrical systems. The proposed AD would require replacing the auxiliary power unit GCU to prevent DC generator overvoltage events. The FAA is soliciting comments until August 9.