This is the story of two remarkable brothers, Harvey and Jim Heyworth. Both had distinguished operational careers in the RAF; both rose to the post of Chief Test Pilot with Rolls-Royce." "Harvey Heyworth began his RAF career in 1931, as a fighter pilot flying Armstrong Whitworth Siskins, and later flew Westland Wallace bombers with No 504 Squadron. In the mid-1930s, after completing his short service commission, he became a Rolls-Royce test pilot, participating in the early development of the Merlin engine. In 1939 he was recalled to the RAF and given command of No 79 Squadron, flying Hurricanes in the Battle of Britain. Still a serving RAF officer, with the rank of wing commander, he returned to Rolls-Royce in 1941." "Meanwhile, Jim Heyworth had also joined the RAF as a bomber pilot, flying Wellingtons and then Lancasters. After two operational tours, during which he was awarded the Distinguished Flying Cross, Jim also joined the Rolls-Royce test team in 1944." "This was the crucial period of aviation history that witnessed the transition from piston to jet, a period that saw Harvey Heyworth become the first man in the world to reach 1,000 hours flying jet aircraft. Later, having survived two serious accidents and become Chief Test Pilot, he went on to test the Rolls-Royce Thrust Measuring Rig - better known as the 'Flying Bedstead', an essential step in the development of the vertical take-off Harrier." "A serious stroke brought an end of Harvey's flying career and led to his early death in 1959. His brother Jim, now appointed Chief Test Pilot, went on to test aircraft such as the Conway-powered Vulcan, and carried out numerous high-altitude trials in the Canberra jet bomber during the days when Britain was at the forefront of aviation technology.