The Dornier Do 31

The Dornier Do 31 was an experimental VTOL (Vertical Take Off and Landing) aircraft developed by Dornier during the late ’60s. With the possibility of war between NATO and the Soviets it was common sense that the first targets of any invading force would be to neutralize enemy airfields and landing strips thus preventing enemy aircraft from taking off. Hence began a dedicated effort towards developing a VTOL aircraft of all kinds. The Do 31 is exceptional not because it is a VTOL aircraft but because it is a VTOL transport. Powered by 8 Rolls-Royce turbojet engines for vertical take off and 2 RR Pegasus engines for forward flight; engineers guaranteed a transport capacity of 3500 Kgs! The West German Airforce put great faith in its VTOL projects which include the Do 31 transport, VFW VAK 191B strike fighter and the EWR VJ 101 fighter.

But it faced the same problem as many VTOL aircraft; the vertical jets were essentially deadweight. One of the alleged contributing factors towards the Do 31’s cancellation was the relatively large drag and weight imposed by the lift engine pods, which reduced both the payload and range of the type compared to typical transport aircraft. It went down as the only VTOL transport jet in history.