As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
ENGINE OIL QUICK DRAIN WOULD NOT SHUT OFF DUE TO ONE SHEARED OFF RIVET HEAD, MS 20470-4, BLOCKING HOLE IN DRAIN VALVE. REF LYC SB 489A. OIL SUMP BAFFLE ASSY HAD THE VERTICAL DEFLECTOR FLANGE MISALIGNED TO BAFFLE PLATE AND THE TENSION LOAD POPPED THE RIVET HEAD OFF. RIVET LOCATED AT AFT END OF FORWARD VERTICAL DEFLECTOR. (X)