As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) DURING A TEST FLIGHT, THE NR 1 PROP WAS FEATHERED TO VERIFY CORRECT FUNCTION OF THE SYSTEM. THE FLIGHT CREW WAS UNABLE TO UNFEATHER THE PROPELLER AND RETURNED TO THE AIRPORT. MAINTENANCE CREWS FUNCTION TESTED THE SYSTEM ON THE GROUND AND THE SYSTEM FUNCTIONED CORRECTLY. THE PROP FEATHERING SOLENOID WAS SUSPECT AND WAS REPLACED. AIRCRAFT WAS RETURNED TO SERVICE. (TC NR 20070620002)