What was found
FLT 4291 - DURING FINAL APPROACH INTO AVL, AIRCRAFT EXPERIENCED A PROPELLER OVERSPEED. CREW DECLARED AN EMERGENCY AND PERFORMED THE IMMEDIATE ACTION ITEMS FOR A PROPELLER OVERSPEED. AIRCRAFT LANDED SAFELY IN AVL. MAINTENANCE REMOVED AND REPLACED LEFT ENGINE AND PROPELLER COMPONENTS. THE TEARDOWN REPORT STATED THAT THE PROPELLER OVERSPEED WAS MOST LIKELY NOT CAUSED BY THE FAILURE OF AN INTERNAL ENGINE COMPONENT OR BY A MALFUNCTION OF THE FUEL SYSTEM OR PROP CONTROL SYSTEM. THE EXACT CAUSE OF THE EVENT REMAINS UNKNOWN, PARTIALLY DUE TO THE LACK OF INFORMATION FROM THE FLIGHT DATA RECORDER MALFUNCTIONING. THIS ENGINE WILL BE SCRAPPED. (M)