What was found
DURING CRUISE, COCKPIT FILLED WITH SMOKE AND HOT AIR AND A DUCT OVERHEAT CONDITION WAS OBSERVED. THE CREW WAS UNABLE TO CONTROL CABIN HEAT VIA COCKPIT TEMPERATURE CONTROL. THE CREW REDUCED POWER AND ALTITUDE IN ORDER TO REDUCE BLEED AIR FLOW THORUGH THE DUCT. THE AIRCRAFT DIVERTED TO THE NEAREST SUITABLE AIRPORT AND LANDED SAFELY. IT WAS LEARNED THAT TORQUE MOTOR FAILED CAUSING UNCONTROLLABLE DUCT HEAT.