Dornier created the Do 31 in West Germany. The plane was a jet transport with vertical take-off and landing functions.
In the midst of the Cold War, the German Air force feared its airfields were susceptible to attack from socialist states. The Do 31 was constructed in compliance to the North American Treaty Organization (NATO) regulations. Dornier programmed the Do 31 for tactical support and transport utilizing its vertical take-off in emergencies.
The plane hit the skies in 1967. The Do 31 reached a maximum speed of 452 mph. The German Air Force cancelled the project three years later due to technical problems and a lack of funding.