What was found
ON FINAL FLT OF DAY, CREW EXPERIENCED PROBLEMS WITH RT ENGINE. PRIOR TO CRUISING ALTITUDE IT WAS NOTICED THE OIL R LIGHT WAS FLICKERING, WHILE OIL PRESSURE GAUGE WAS OSCILLATING BETWEEN 90 PSI AND 135 PSI. GAUGE CONTINUED WITH ITS OSCILLATIONS, BUT THE RANGE LOWERED TO 80 PSI AND 120 PSI. TREND CONTINUED DOWN, SHUT DOWN ENG WHEN PSI DROPPED BELOW 60PSI. LANDED SAFELY. MECHANICS DISPATCHED, OIL WAS ADDED, DISCREPANCY WAS NOT CORRECTED. SERVICEABLE ENG WAS INSTALLED. OPS CHECKED GOOD. AC RETURNED TO SERVICE.