As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ON RETURN FLIGHT PILOTS REPORT THAT RT PROPLLER RPM STAYED AT 2100. THEY WERE NOT ABLE TO GOVERN PROPELLER SPEED. AFTER LANDING MAINTENACE CHECKED THE SYSTEM AND DETERMINED THAT REPLACEMENT OF PROP. GOVERNOR WAS REQUIRED. AFTER REPLACEMENT WITH A SERVICABLE PART, FUNCTION CHECK WAS COMPLETED AND OPERATION WAS NORMAL.