What was found
INFLIGHT , RT ENGINE TORQUE GAGE BEGAN TO FLUCTUATE ON THE RETURN LEG BACK TO DEPARTURE. WITHIN TWO MINUTES, RT ENGINE OIL PRESSURE GAGE STARTED TO FLUCTUATE AS WELL. FLUCTUATED BETWEEN 100PSI, AND 50PSI RAPIDLY. A MINUTE OR TWO LATER THE RT OIL PRESSURE GAGE WAS DIPPING BELOW 50PSI (RED LINE), THEN STOPPED FLUCTUATING AND STAYED BELOW RED LINE. FLIGHT CREW PERFORM A PRECAUTIONARY ENGINE SHUTDOWN. RETURNED TO THE AIRPORT. ACFT LANDED WITHOUT INCIDENT.