Description of the radar set, tactical-technical characteristics
Figure 1: AI.23
|pulse repetition time (PRT):|
|pulse repetition frequency (PRF):||1 000 Hz|
|pulsewidth (τ):||1 µs|
|peak power:||100 kW|
|instrumented range:||40 NM (≙ 74 km)|
|hits per scan:|
AI.23 (Radar, Airborne Interception, Mark 23) alias AIRPASS (Airborne Interception Radar and Pilot’s Attack Sight System) was operating in X-Band tracking radar designed for the British supersonic fighter Lightning F.6. It was the first high power radar with monopulse tracking to go into Squadron service anywhere in the World. The radar was used to point and fire the Firestreak and Red Top air-to-air missile. The latter was used for Head-on Supersonic Intercepts.
The radar was a classic pulse radar with a transmitter using a magnetron type 65638/21. The technology was entirely analogue using miniature wire-ended vacuum tubes, wire-wrapped connections and forced-air cooling.
420 radar sets were produced throughout the 1960’s, 70’s and 80’s with improving developments ending with AI.23D. The next version of the system was called AIRPASS II (also known as Blue Parrot) was fitted to Buccaneer aircraft. In between, the radar was also produced by Marconi Electronic Systems (MES). The AI.23 radar was flown by RAF and also the Royal Saudi Arabian and Kuwait Air Forces. The radar was withdrawn from service in April 1988.