What was found
FLT 4563 - WHILE CLIMBING OUT OF FWA, AT 21,000 FEET, THE LEFT ENGINE N2 VIBRATION SPIKED APPROXIMATELY 2.6 MILS. THE FLIGHT ATTENDANT AND PASSENGERS REPORTED A LOUD NOISE FROM THE LEFT ENGINE. THE LEFT ENGINE SHUT ITSELF DOWN. THE CAPTAIN DECLARED AN EMERGENCY AND RETURNED TO FWA FOR AN OVERWEIGHT LANDING. MAINTENANCE PERFORMED THE OVERWEIGHT LANDING INSPECTION. NO DEFECTS WERE NOTED. THE LEFT ENGINE WAS REMOVED AND REPLACED. THE MRR WILL REMAIN OPEN PENDING RESULTS OF ENGINE TEARDOWN. (M)