FOLLOWING HIRAM OTWELL’S largely ignored innovation of changing the thrust angle by inclining the entire engine nacelle, a number of designers independently arrived at the same solution. The earliest after Otwell was British designer Leslie Baynes, who developed the strikingly modern-looking Baynes Heliplane in the late 1930s and early 1940s. Baynes’s patents in 1937 and 1938 sought to combine some advantages of both helicopter and aeroplane, with an aircraft mounting a rotor at each wingtip that could articulate through 90°, driven by shafts from a fuselage-mounted engine. Baynes also innovated a novel form of propulsion, using a free-piston gas-generator in the fuselage supplying hot gases to a turbine. In 1940 Baynes combined both ideas into a heliplane with turbines in wingtip-mounted nacelles, which could swivel from vertical to horizontal. Wartime pressures saw that the idea never progressed.