AIRPASS (Airborne Interception Radar & Pilot's Attack Sight System) was a British airborne interception radar and fire-control radar system developed by Ferranti. It was the world's first airborne monopulse radar system, and provided direction to the world's first head-up display.
The AIRPASS system was announced in late June 1958 and the radar was carried by interceptor aircraft from the early 1960s. It was initially linked to the de Havilland Firestreak air-to-air missile. Also known as the Ferranti AI.23. AIRPASS was developed by Ferranti Ltd on Ferry Road in Edinburgh. It introduced the HOTAS (Hands On Throttle-And-Stick) system whereby the radar and gun sight controls were situated on the control column and throttle lever instead of elsewhere in the cockpit, eliminating the need for the pilot to take his hands off the controls while making an interception.
The radar entered service with the RAF in 1960 in the English Electric Lightning interceptor. The next version of the system was called AIRPASS II, or "Blue Parrot", and was a system optimised for use at low-level and originally developed for the cancelled BAC TSR.2 and subsequently used in the Blackburn Buccaneer.
The radar system allowed the aircraft to find hostile aircraft. It had search and automatic track modes.
The radar of AIRPASS I weighed around 90kg.