As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
VIBRATIONS WERE FELT DURING CLIMB OUT. THEY WERE MORE NOTICEABLE WHEN CONDITION LEVERS WERE AT 1020 AND 900. VIBRATIONS WERE LESS ONCE CONDITION LEVERS WERE SET AT 850 AND TORQUE WAS BELOW 55%, THEN DURING DESCENT VIBRATIONS INCREASED AGAIN WHEN TORQUE WAS APPROXIMATELY 35% TORQUE. RETURN TO FIELD, LANDING UNEVENTFUL. REMOVED FROM SERVICE, REF W/O 290397 FOR REPLACEMENT OF THE NR 1 PROPELLER. RETURNED TO SERVICE.