FAA Proposes Bombardier CL-600 AD on Air-Driven Generator
The FAA proposes to issue an airworthiness directive for certain variants of the Bombardier CL-600, 601 and 604. According to the FAA there have been several occurrences of the air driven generator (ADG) failure to power essential buses during functional tests of the ADG. It was found that the low threshold setting of the circuit protection on the ADG generator control unit (GCU) can prevent the supply of power from the ADG to the essential buses. In the event of an emergency, loss of power to the essential buses can prevent continued safe flight.