de Havilland Firestreak

The de Havilland Firestreak is a British first-generation, passive infrared homing (heat seeking) air-to-air missile. It was developed by de Havilland Propellers (later Hawker Siddeley Dynamics) in the early 1950s, entering service in 1957. It was the first such weapon to enter active service with the Royal Air Force (RAF) and Fleet Air Arm, equipping the English Electric Lightning interceptor, de Havilland Sea Vixen naval fighter and the Gloster Javelin all weather interceptor. It was a rear-aspect, fire and forget pursuit weapon, with a field of attack in a rear-facing 20 degree cone.
Developed under the rainbow code "Blue Jay", Firestreak was the third heat-seeking missile to enter service, after the US AIM-4 Falcon and AIM-9 Sidewinder, both of which entered service the previous year. In comparison to those designs, the Firestreak was larger and almost twice as heavy, carrying a much larger warhead. It had otherwise similar performance in terms of speed and range. It was also a very complex system, with an unusual internal design, requiring the launch aircraft to provide both cooling for its valve-based electronics and heating to prevent various moving parts from freezing prior...