Shaping the Future through the Past – The Beginning of Leonardo Helicopters’ Journey in Convertible Rotorcraft Design

The United Kingdom's convertible rotorcraft studies of the 1960s and early 1970s represent a systematic effort to combine vertical take-off and landing capability of helicopters with the speed and efficiency of fixed-wing transport aircraft. Conducted primarily by Westland Helicopters under the Short Range Transport (SRT) programme, these investigations explored both tiltrotor and tiltwing configurations for civil and military applications. Early work focused on the WE-01 tiltrotor, conceived as a research and demonstrator aircraft to investigate transition aerodynamics, control integration, and rotor–wing interactions, and subsequently scaled to the larger WE-02, intended for intercity and tactical transport missions. In parallel, Westland pursued the more ambitious WG.22 tiltwing, a 100-seat intercity VTOL transport incorporating high-incidence stall wing technology, large prop-rotors, and mechanically scheduled flight controls to ensure benign handling through transition. Although none of these aircraft were built, the studies addressed aerodynamics, structures, propulsion, flight controls, noise, and socio-economic viability with exceptional depth. Shaping the future through the past, this paper revisits Westland's early involvement in tiltrotor and tiltwing research, with the aim of assessing the technical maturity of these configurations and evaluating their lasting relevance to contemporary vertical lift aircraft design.