What was found
(CAN) DURING CRUISE, IT APPEARS THAT THE CABIN CREW SAW FIRE OUT OF THE NO. 1 ENGINE AND REPORTED IT TO THE PILOT WHO SHUT DOWN AND SECURED THE ENGINE BEFORE DISCHARGING THE FIRE BOTTLES. THE CREW PERFORMED A SINGLE ENGINE LANDING WITHOUT FURTHER PROBLEMS. TROUBLESHOOT THE ENGINE AS NECESSARY. A LOOSE B - NUT WAS FOUND AT THE FUEL FLOW TRANSMITTER WHICH ALLOWED THE FUEL LEAKAGE AT THE SOURCE OF THE FIRE.