What was found
PIT - FL541 - CAPTAIN ADVISED THAT CLIMBING THROUGH 10, 000 FT, THE NR 1 ENGINE OILQTY INDICATED A STEADY LOSS OF OIL. CREW SHUT DOWN THE NR 1 ENGINE WITH 5 QUARTS OF OIL REMAINING AND DECLARED AN EMERGENCY. FLIGHT RETURNED TO FIELD AT PIT AND LANDED WITHOUT FURTHER INCIDENT. TOTAL SINGLE ENGINE TIME WAS 11 MINUTES. MAINTENANCE FOUND THE O-RING ON THE NR 1 ENGINE FUEL/OIL COOLER OUTLET LINE CUT IN HALF. REPLACED SAME. TIGHTENED B-NUTS AND SAFTIED. RAN ENGINE. LEAK CHECK GOOD. (M)