What was found
(CAN) DURING APPROACH AT 400-500 FT ALTITUDE, PILOT HEARD A BANGING SOUND, NR 2 ENGINE OIL PRESSURE DROPPED, TEMPERATURE WAS RAISING, CHIP LIGHT ILLUMINATED. PILOT MAINTAINED THE ENGINE NR 1 TORQUE AT 55 PERCENT WHILE NR 2 TORQUE WAS AT ZERO. PILOT SAFELY LANDED WITHIN 2 MINUTES. DURING THE INSPECTION AND INVESTIGATION OF THE REASON, IT WAS OBSERVED THAT OIL HAD DRAINED COMPLETELY FROM THE OIL DRAIN BUTTERFLY AND A PIECE OF COMPRESSOR BLADE WAS FOUND FROM PS NR 2 ENGINE.