As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A ROUTINE 600 HR ENGINE INSPECTION, IT WAS NOTED THAT THE ENGINE INTERNAL OIL FILTER WAS MISSING. DETERMINED THAT THE ENGINE WAS OPERATED FOR THE LAST 600 HRS WITHOUT A FILTER ELEMENT INSTALLED. A NEW FILTER ELEMENT WAS INSTALLED AND THE OIL SYS WAS FLUSHED AND SERVICED. PULLED AN OIL SAMPLE BEFORE DRAINING THE SYS AND SEND IT FOR EVALUATION. EVALUATION WAS RETURNED WITH ALL NORMAL WEAR INDICATED.