What was found
DURING A ROUTINE 100 HR INSPECTION, IT WAS DISCOVERED THAT 2 OF THE 4 BLADES ON EACH OF THE 2 HARTZELL PROPELLERS HAD A ROUGH MOVEMENT WHEN ROTATED FROM REVERSE PITCH TO FEATHER POSITION AND BACK AGAIN. SENT BOTH PROPS TO A PROPELLER O/H FACILITY AND FOUND THE BEARINGS ON THE ROUGH BLADES WERE WORN TO THE LIMITS. THIS IS THE SECOND TIME DISCOVERED THIS PROBLEM ON THE 4 BLADED HARTZELL PROPELLERS INSTALLED ON THE MU-2 AIRCRAFT.