As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ACFT EXPERIENCED TORQUE FLUCTUATIONS IN CRUISE AND DESCENT 2.5 PERCENT. THE PROPELLER SHAFT SPEED NP WAS ALSO DROPPING 1 PERCENT. AIRCRAFT RETURNED TO BASE AND THE PROP CONTROL UNIT WAS FOUND AT FAULT. PCU REPLACED AND FLIGHT TEST COMPLETED, SATISFACTORY.