As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT ENGINE ON AIRCRAFT WOULD NOT MAKE RPM OR CYCLE PROPELLER. BA59 BEARING FOUND IN LEFT ENGINE GOVERNOR, THIS UNIT THE RIGHT ENGINE PROPELLER GOVERNOR REMOVED TO INSPECT AS PRECAUTION AND TO COMPLY WITH AD 2020-19-06 AND MCCAULEY ASB273C. THIS GOVERNOR WAS FOUND TO CONTAIN THE BA59 BEARING IN PROGRESS OF FAILURE. UNIT IS DAMAGED BEYOND ECONOMICAL REPAIR.