As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN)DURING A FLIGHT TEST, COMING OFF FINAL APPROACH, THE RIGHT HAND PROPELLER STARTED FLUCTUATING BETWEEN 13300 AND 14400 RPM. THE R/H ENGINE WAS SHUT DOWN AND THE AIRCRAFT LANDED WITHOUT INCIDENT. THE PROPELLER WAS REMOVED AND SENT FOR INSPECITON/OVERHAUL.