What was found
(CAN) LIGHT TO MODERATE PROP VIBRATION IN CRUISE, AS POWER WAS REDUCED FOR DESCENT VIBRATION BECAME EXCESSIVE. AS A RESULT THE NR 1 PROP (CONDITION LEVER) WAS SELECTED TO START FEATHER (VIBRATION STOP) AND THEN NR 1 ENGINE WAS SHUTDOWN. ALL ENGINE PARAMETERS WERE NORMAL PRIOR TO SHUTDOWN. FOLLOWING THE IFSD AS DESCRIBED ABOVE, MAINTENANCE PERFORMED A LOW POWER RUN TO VERIFY THE VIBRATION AS REPORTED. THE VIB WAS CONFIRMED AND THE ENGINE SHUTDOWN. OIL WAS THEN NOTED DRIPPING FROM THE VICINITY OF THE NR 1 PROP. INITIAL INVESTIGATION HAS REVEALED THAT THE NR 1 PROP, NR 4 BLADE BEARING RACE HAS FRAGMENTED INTO SEVERAL PARTS. (TC NR 20061211005)