What was found
AT FL 166, NR 4 ENGINE SURGED, TORQUE, T5 AND NG ALL WENT TO MAX. ENGINE WAS SHUT DOWN AND SECURED. AIRCRAFT LANDED AT DEN WITHOUT FURTHER INCIDENT. AIRCRAFT WAS THREE ENGINE FERRIED TO A MAINTENANCE BASE. UPON INVESTIGATION, FOUND ENGINE FUEL PUMP TO FUEL CONTROL DRIVE COUPLING SHEARED. ENGINE AND PROPELLER ARE TO BE REMOVED FOR OVERSPEED/OVERTORQUE INSPECTION, REPAIR AND/OR OVERHAUL. (X)