What was found
DURING DESCENT TO ROU RT PROPELLOR RPM BECAME UNCONTROLLABLE. PROPELLOR RPM WENT TO 104 PERCENT. CREW WAS UNABLE TO LOWER THE RPM TO 100 PERCENT WITH THE SPEED LEVER. A PRECAUTIONARY RT ENGINE SHUT OFF WAS PERFORMED. A/C LANDED AND TAXIED TO GATE WITHOUT FURTHER INCIDENTS. THE RT PROP WAS REPLACED AND A/C RETURNED TO SERVICE. PROPELLER WAS RETURNED TO VENDOR FOR EVALUATION. TEAR-DOWN REPORT WAS RECEIVED 10/26/00 CAUSE OF UNCONTROLLABLE PROPELLOR RPM WAS IMPROPER BLADE SHIMMING. ALL BLADES WERE SHIMMED TO CORRECT BLADE TORQUE.