As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PILOT STATED THAT DURING CRUISE FLIGHT, PROPELLER WENT TO FINE PITCH, AND OPERATION OF GOVERNOR CONTROLS HAD NO EFFECT. UPON GROUND RUN UP IT WAS FOUND THAT PROP WOULD NOT CYCLE. REMOVED FROM SERVICE. UNKNOWN CAUSE FOR FAILURE AT THIS TIME. (AL05200401344)