Abstract: An aircraft fire protection system includes a plurality of extinguishant bottles which can be detonated to deliver extinguishant into a manifold and then to selected fire zones through valves associated with the respective fire zones. Solid state control circuitry opens the appropriate valve when a corresponding push button switch is initially depressed and detonates one or more bottles in sequence when the same switch is subsequently depressed one or more times. A manual crash switch opens all valves when depressed once and discharges all bottles when depressed again. An automatic crash switch opens all valves and detonates all bottles if the aircraft should crash. A test circuit operates in a test mode to open all valves in sequence and to simulate sequential detonation of all bottles by applying low level current to the bottle detonator circuits.