As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) RUDDER TRIM RUNAWAY. PILOT REPORTS SHORTLY AFTER TAKEOFF HE ROTATED THE RUDDER TRIM KNOB & WHEN HE LET GO OF THE RUDDER TRIM KNOB, IT WOULD NOT STOP TRIMMING & CONTINUED TO TRIM THE RUDDER IN THE PREVIOUS SELECTED DIRECTION. HE SELECTED THE RUDDER TRIM BACK TO THE OTHER DIRECTION & FINALLY IT BEGAN TO COME BACK TO CENTER. THE PILOT ELECTED TO DIVERT BACK TO HOME BASE AIRPORT FROM WHICH HE HAD TAKEN OFF. LANDING WAS UNEVENTFUL & THE TRIP WAS CANCELLED.