Then there was the AVPIN System, developed for RAF aircraft to overcome the limitations of the Coffman system.
AVPIN is isopropyl nitrate, it burns without additional air and has an invisible flame, although the products of combustion are pungent.
Isopropyl nitrate was also sold by the Turbonique company under the brand name "Thermolene" as a fuel for their line of turbine-powered "drag axles" and superchargers, during the 1960s.
