What was found
(CAN) ON APPROACH, THE CREW REPORTED FLASHES OF LIGHT COMING FROM NR 1 ENGINE EXHAUST. THIS WAS FOLLOWED IMMEDIATELY BY A SLIGHT YAWING OF THE AIRCRAFT. TORQUE FLUCTUATIONS AND AN INCREASE IN ITT ON THE NR 1 ENGINE. THE ENGINE WAS SHUT DOWN. THERE WAS MILD TO MEDIUM SMOKE CONTAMINATION IN THE CABIN, THE OXYGEN MASKS WERE DEPLOYED, AND THE SMOKE EVACUATED. THE LANDING WAS UNEVENTFUL. POST-FLIGHT INSPECTION FOUND THE 1ST STAGE COMPRESSOR DIFFICULT TO TURN BY HAND AND OIL COMING FROM THE AIR INLET INDICATING A FAILURE OF NR 1 BEARING, BUT THIS IS NOT CONFIRMED. FURTHER REPORT TO FOLLOW.