The story begins in 1940 when Harvey Heyworth was leading No. 79 Squadron RAF defending north-eastern England from Luftwaffe raids made by bombers based in Norway and Denmark and then later in the Battle of Britain when the unit moved south. During late 1940 and up to June 1941 Heyworth led his squadron in defence of Bristol and Swansea operating by night and day. By 1942 he had amassed 4,000 flying hours. Harvey then joined Rolls-Royce test flying early British jet aircraft including the famous Gloster-Whittle and test-bed Wellington bombers powered by the new jet engines. In 1944 Harvey's brother Jim also joined Rolls, having flown with No. 12 Squadron in Bomber Command. The story then unfolds into the development of the Trent turboprop and the Avon jet engines. Development work on a variety of test-bed aircraft was ongoing and included some weird combinations of airframe and engine.Jim succeeded his brother as chief test pilot in 1958 and flew 82 different aircraft types. He recounts his experiences of piloting the Vulcan bomber, Lightning and the 'Flying Bedstead' VTOL test rig.