What was found
(CAN) THE AIRCRAFT LANDED IN EMERGENCY DUE TO AN IFSD OF THE RT ENGINE DURING ASCENT PASSING 4000 FT. THE PILOT NOTED A DROP OF TORQUE, THEN NG AND NP, WITH THE ITT GOING UP. THERE WAS NO ACCELERATION CONTROL. THE PILOT FEATHERED THE PROPELLER AND LANDED SAFELY. ON GROUND THEY VISUALLY INSPECTED THE ENGINE AND NOTED METALLIC MATERIAL FROM THE EXHAUST DUCTS.