As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
SHIP 393 - ATB - THS WHEEL MOVES ERRATICALLY AND FAST WHEN AUTOPILOT IS ON. WHEN AUTOPILOT IS OFF, TRIM FEELS NORMAL. CORRECTIVE ACTION: "FCPC 1 (2EC1) PITCH TRIM ACT (1CS) OVERRIDE SWITCH" FAULT ON PFR. T/S. REMOVED AND REPLACED PITCH TRIM ACTUATOR. OPS CHECKED. (7273861)