As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
IN CRUISE FLIGHT THE NUMBER ONE ENGINE WAS OBSERVED LOOSING OIL PRESSURE SLOWLY. OIL PRESSURE DROPPED TO RED LINE THEN BEGAN TO CLIMB BACK TO INTO THE GREEN ARC. OIL TEMP AND ALL OTHER ENGINE PARAMETERS STAYED NORMAL SO IN WAS BELIEVE THIS WAS AN INDICATION ERROR. TROUBLE SHOOTING ON THE GROUND CONFIRMED THE PROBLEM WAS AN INTERNAL FAILURE OF THE OIL PRESSURE TRANSDUCER ON THE NUMBER ONE ENGINE.