up on enemy aircraft without giving themselves away by using their own radar sets. Typically, to perform an interception by themselves beyond visual range, the aircraft would have to search the sky for intruders with their radars, the energy from which might be noticed by the intruder's radar warning receiver (RWR) electronics, thus alerting the intruders that they may be coming under attack. With GCI or AEW&C, the defending aircraft can be vectored to an interception course, perhaps sliding in on the intruder's tail position without being noticed, firing passive homing missiles and then turning away. Alternatively, they could turn their radars on at the final moment, so that they can get a radar lock and guide their missiles. This greatly increases the interceptor's chance of success and survival. See also Signal Corps Radio Sector clock ROTOR Linesman/Mediator Boeing Ground-to-Air Pilotless Aircraft UCAV STRIL References Radarpages.co.uk GCI page Jindalee over-the-horizon radar GCI Online Radar Museum External links Ground Controlled Interception Radars in Operation Neptune/Overlord (pdf) Ground-controlled Military radars