The FAA has issued an airworthiness directive for the Cessna 750’s auxiliary power unit DC generator prompted by overvoltage events. The AD requires replacing the APU generator control unit to prevent DC generator overvoltage events, which could result in smoke in the cockpit and loss of avionics and electrical systems. On June 25 a notice of proposed rulemaking was issued proposing the APU generator control unit be replaced and the public was given the opportunity to comment.
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.