The Dornier Do 231 was a 1970s VTOL transport aircraft project developed by Dornier.
The Do 231 was a result of a design competition conducted in the early 1970s by the German Federal Ministry of Economics to create a 100-person VTOL transport aircraft. Based on the earlier Do 31, the Do 231 was to have shoulder-mounted cantilever swept wings and a T-tail.[1]
The 1973 oil crisis rendered the Do 231 proposal as uneconomical due to the high fuel consumption necessary for vertical takeoff and landing, and the aircraft was cancelled in 1976 without a single prototype being built.
