What was found
(CAN) DURING CRUISE, THE NR 1 ENGINE OIL PRESSURE FLUCTUATED 50-60 PSI. LOW OIL PRESSURE CAUTION LIGHT INTERMITTENT. POWER REDUCED. LANDING NORMAL. INSPECTION FOUND LOW OIL QUANTITY DUE TO A LARGE LEAK FROM OIL COOLER INLET FITTING. THE COOLER RIGID LINE HAD CHAFED THE FITTING ALLOWING OIL TO LEAK PAST THE PACKING. P/N AS3209-219. LINE WAS BELIEVED TO HAVE BEEN COCKED AT INSTALLATION.