An overview of V/STOL aircraft development

In reviewing the years of aviation development, it can be seen that vertical-takeoff-and-landing (VTOL) flight was considered before conventional fixed-wing operations. However, it has been difficult to develop a VTOL capability. The present investigation is concerned with a review of the historical development of VTOL aircraft, taking into account lessons learned from a selected group of concepts. Attention is given to the Flying Bedsteads, the tail-sitter designs, the Air Test Vehicle (ATV) and X-14 aircraft, the SC-1, the XV-3 tilt-rotor aircraft, the VZ3-RY deflected slipstream, the X-18 tilt wing, the VZ-2 tilt wing, the VZ-4 ducted fan, the Harrier, the XV-4A (Hummingbird), the Forger, and the XV-15 advanced tilt rotor.