As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PRESSURE SWITCH FAILED THAT CONTROLS THE HOBBS METER AND THE FAILURE ALLOWED OIL TO FLOW OUT OF THE ENGINE. THE PROBLEM WAS FOUND DURING A PRE-FLIGHT INSPECTION OF THE AIRCRAFT. ESTIMATED THAT THE AIRCRAFT WOULD HAVE 1GT OF OIL AN HOOUR OR MORE WITH THE OIL LOSS THAT DID OCCUR.