What was found
FLIGHT 450, AFTER TAKEOFF, CAPTAIN NOTICED LOUD (BANG) AND FLAMES COMING FROM LT ENGINE. PRIOR TO NOISE, ALL INDICATIONS REPORTED AS NORMAL. NO T-HANDLE (FIRE PULL) LIGHTS ILLUMINATED. CREW SHUT DOWN LT ENGINE, DISCHARGED LT FIRE BOTTLE, FIRE EXTINGUISHED AND AIRCRAFT RETURNED TO DEPARTURE WITHOUT FURTHER INCIDENT. PASSENGERS WERE EVACUATED WITH ASSISTANCE OF AIRPORT EMERGENCY PERSONNEL WITH NO FURTHER INCIDENTS. SUBSEQUENT OBSERVATIONS BY COMPANY MAINTENANCE PERSONNEL SENT TO THE AIRCRAFT CONFIRMED (LT ENGINE HARD TO TURN BY HAND). NO EXTERNAL DAMAGE IN ENGINE COMPARTMENT OR EXCESSIVE OIL LEAKAGE NOTED. SUSPECT INTERNAL BRG FAILURE AS OF 1/18/07. ENGINE CURRENTLY BEING REMOVED FOR SHIPMENT AS A UNIT TO MFG F