Dornier Do 231

The Dornier Do 231 was a project for a large vertical take-off and landing transport aircraft, studied by Dornier in the early 1970s. It grew out of a design competition run by the German Federal Ministry of Economics for a transport able to carry 100 people, and it was based on the experience of the earlier Do 31. The design had shoulder-mounted swept wings and a T-tail, with two Rolls-Royce RB.220 jet engines for cruise and twelve RB.202 lift engines for vertical flight. A civil version for Lufthansa and a military version with a stretched fuselage and rear loading ramp were drawn up. The oil crisis of 1973 made the fuel appetite of vertical take-off uneconomical, and the aircraft was cancelled in 1976 without any prototype being built.