 The Short SB.4 Sherpa was designed by David Keith-Lucas as a research aircraft aimed primarily at assisting in the development of wings for faster, very high-altitude aircraft in general and the company's Preliminary Design (Short PD.1) in response to the U.K. V-Bomber requirement B35/46 in particular.It was the first powered aircraft to employ the "aero-isoclinic" wing first proposed in 1951 by Professor Geoffrey T.R.Hill, who had been instrumental in the design of the Westland-Hill Pterodactyl tail-less experimental aircraft in the mid-1920s.