As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) IN CRUISE FLIGHT, NR 1 ENGINE HAD A VIBRATION STARTING AT 57 PERCENT TORQUE AND INCREASED AS TORQUE INCREASED. VIBRATION STOPPED BELOW 57 PERCENT TORQUE. ALL OTHER ENGINE INDICATIONS NORMAL. MAINTENANCE REPLACED PROPELLER ASSY TEARDOWN REVEALED DAMAGED BEARING LINERS.