What was found
INSTALLED A LOANER AIR DRIVEN GENERATOR (ADG) DUE TO SURFACE CORROSION ON THE GENERATOR SHAFT AND NUT THAT WAS FOUND ON AN INSPECTION. COMPLETED AN IN-FLIGHT CHECK TO OPERATE THE ADG AND FOUND THE ADG INOPERATIVE AT THAT TIME. RETURNED TO HANGAR AND REINSTALLED THE PREVIOUSLY REMOVED ADG. TROUBLESHOOTING REVEALED THAT THE LOANER ADG HAD DAMAGED TWO OTHER COMPONENTS IN THE SYSTEM DURING THE OPERATIONAL CHECK. THE ADG AUTO CONTROL UNIT AND THE ADG GENERATOR CONTROL UNIT. INSTALLED NEW PARTS AND THEN COMPLETED A SATISFACTORY IN FLIGHT OPERATIONAL CHECK OF THE ADG SYSTEM.