What was found
ON DESCENT, MOMENTARY WHITE SMOKE ON COCKPIT AND A MUSTY OILY SMELL IN CABIN AND COCKPIT. GALLEYS AND GASPER FANS TURNED OFF CABIN RAISED TO 9500 FT SMOKE AND SMELL DISSIPATED. RAN ENGINES FOUND LEFT PACK OVERHEATING BUT WOULD NOT TRIP. REPLACED TURBINE INLET OVER HEAT SWITCH AND TURBINE INLET OVERHEAT SWITCH AND DUCT OVERHEAT 250 DEGREE SWITCH. RAN ENGINES, LEFT PACK OPS CKS OK.