Abstract: An acoustic flame-out detection system that renders a large high pressure combustor 12 (FIG. 1) safe in the event of a flame-out and possible explosive reignition. A dynamic pressure transducer 22 is placed in the fuel line 16 and detects the stabilizing fuel pressure oscillations, caused by the combustion process. An electric circuit (FIG. 5) converts the signal from the combustion vortices, and transmitted to the fuel flow, to a series of pulses. A missing pulse detector 39 counts the pulses and continuously resets itself. If three consecutive pulses are missing, the circuit closes the fuel valve 20. With fuel denied, the combustor 12 is shut down or restarted under controlled conditions.