What was found
(CAN) IFSD DURING REVENUE FLIGHT PILOTS NOTED OIL PRESSURE DROPPED TO 25 PSI IN CLIMB. OIL PRESSURE RECOVERED TO NORMAL RANGE AFTER A FEW SECONDS. SUBSEQUENTLY, DURING CRUISE, A SIGNIFICANT DROP OF OIL PRESSURE OCCURRED. PILOTS REDUCED ENGINE POWER TO FLIGHT IDLE, OIL PRESSURE DROPPED TO ZERO AFTER ABOUT 10 MINUTES IN FLIGHT PILOT SHUTDOWN ENGINE AND DIVERTED TO CLOSEST AIRPORT WHERE AN UNEVENTFUL SINGLE ENGINE LANDING WAS PERFORMED. TROUBLESHOOTING IS ONGOING.