What was found
WHILE SITTING AT THE END OF RUNWAY, AIRCRAFT WAS CLEAR FOR TAKEOFF. CREW ADVANCED THROTTLES. WHILE SPOOLING UP TO N1 FOR TAKEOFF, THE LEFT ENGINE RELEASED A LOUD EXPLOSION. THROTTLES WERE RETARDED, TRIP WAS CANCELLED. THE AIRCRAFT TAXIED TO A MAINTENANCE FACILITY. INITIAL INSPECTION IDENTIFIED THE AFT TURBINE WHEEL MISSING SEVERAL SECTIONS OF BLADES. THE SHROUD WAS DAMAGED AND HAD SOME HOLES IN IT. A BORESCOPE OF THE COMBUSTION CHAMBER REVEALED METAL SPRAY. THE ENGINE IS BEING REMOVED FOR FURTHER INVESTIGATION AND REPAIR. 4,522 CSN. (X)