What was found
(CAN) AT EIGHT THOUSAND FEET WHILE SLOWING THROUGH 160 KTS, ON THE TC CHECK RIDE, NR 3 PROP OVERSPEED TO 14,550 ERPM. THE ENGINE WAS SHUT DOWN AND PROP FEATHERED. THE A/C RETURNED TO CYQF AND LANDED WITHOUT INCIDENTS. MAINTENANCE FOUND ROTARY ACTUATOR DRIVEN PAST LIMITS. UNIT REPLACED, ALL GROUND RUNS PERFORMED AND NO FAULTS FOUND.