Airborne Interception Radar also called AI, is a radar tracker developed around the time of World War Two, and installed into airplanes. It gave the British a very big advantage over the attacking German Fighters. It was a crucial part of the war effort, and without it the Germans may have been able to take over Great Britain.

What is Airborne Interception Radar?

Bristol Beaufighter, first plane where the radar was mass produced.

Airborne Interception Radar System.

http://en.m.wikipedia.org/wiki/Cavity_magnetron

http://commons.m.wikimedia.org/wiki/File:Bristol_Beaufighter_NAN15Dec43.jpg