This illustrated book describes the projects and design studies carried out by the UK’s aircraft companies to produce an airborne early warning (AEW) aircraft for the Royal Air Force. It covers the earliest Wellington ACI and Operation Vapour attempts at AEW, along with Bomber Command’s use of Fishpond to concentrate raids and the search for its Big Picture system. Post-war Hamilcar trials of the airborne warning and interception (AWI) system also came to naught in the cash-strapped Forties. The improvements in radar technology in the Sixties and Seventies saw a resumption of AEW studies including the VC10, BAC 1-11, Britannia and of course, the Nimrod. The story ends in the Eighties with the saga of Nimrod AEW.3 and the Air Staff getting what it had wanted since the inception of the type: Sentry.