During the late 1940s and into the 1950s, a number of British jet fighter and bomber aircraft were fitted with new, different or additional engines, both jet and rocket, to enable them to serve as test beds for those specific powerplants. These aircraft types included fighters such as the de Havilland Vampire, Gloster Meteor and Javelin, and Hawker Hunter, the one-off Hawker P.1072 and the English Electric Canberra, Short Sperrin, Vickers Valiant and Avro Vulcan bombers. This book brings together these specific aircraft, and the engines they tested, in a single volume. Accompanied by over 200 images, some of which are published here for the first time, it is an invaluable reference tool for both aviation enthusiasts interested in experimental and trails aircraft and modelers specializing in jet aircraft.