As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) COMMENCING THE DESCENT, THE CREW OBSERVED OIL PRESSURE FLUCTUATION ON THE NR 1 ENGINE ACCOMPANIED BY 2 FLASHES OF THE RED LOCAL ALERT. NO CCAS ALERT WAS OBSERVED. THE ACFT RETURNED TO POINT OF DEPARTURE AND LANDED WITHOUT FURTHER PROBLEM. MX OBSERVED A LOSS OF ENGINE OIL CONDITION AND DETERMINED THAT THE ENGINE OIL COOLER WAS THE SOURCE OF THE LEAK. THE ACFT IS AWAITING REPLACEMENT PARTS.