As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) PROP WOULD NOT CHANGE PITCH DURING RUN-UP. GEARBOX WAS REMOVED AND THE SCREW HOLDING THE GOVENOR DRIVE COUPLING TO THE DRIVE GEAR WAS FOUND BROKEN. THE SCREW APPEARED TO HAVE FAILED FROM TORQUE OVERLOAD. THE SCREW, DRIVE COUPLING AND GEAR WERE REPLACED AND ENGINE RETURNED TO SERVICE. NO FOD NOTED. THE ENGINE HAS 577 HRS SINCE OVERHAUL. (TC NR 20060929003)