Abstract: A heat responsive fire extinguishing system is disclosed which includes a delivery tube, supported relative to and about the ceiling of a passenger compartment, for example, of an aircraft or other vehicle such as a boat.

Abstract: A heat responsive fire extinguishing system including at least one delivery tube having a plurality of strategically spaced apart openings directed towards the area to be protected, each of the openings being closed by a plug of a suitable material having relatively low temperature fusion points, and wherein a flexible tensioned trigger line operable by the existance of an above normal ambient temperature to open and release a spring tensioned or gravity operated valve to direct a flow of a suitable pressurized fire extinguishing material into the delivery tube and wherein the plugs, exposed to the above normal ambient temperature, will be softened and blown out of the tube holes by the pressure forces of the fire extinguishing material in the tube to discharge fire extinguishing material through the holes to supress or extinguish any surrounding flames.