For any manufacturer an annular -wing vertical take-off and landing jet was a step into the unknown, let alone for one that built engines rather than aircraft. Unsurprisingly, the pr SNECMA C450 Coléoptère — French for beetle — was a one-off its career cut short by a fiery accident, the cause of which remained secret for decades

Helmut von Zborowski’s was a fertile mind. The director of the rocket propulsion department at during the Second World War, just after hostilities ended he came up with the idea of coupling the propulsion of a flying object with an annular wing, the axis of thrust being the same as that of the wing. His old colleague Hermann Östrich, once BMW’s head of turbojet development, had become director of a research group at SNECMA — the Société nationale d’études et de construction de moteurs d’aviation — and already recruited some former German scientists. They arranged a meeting, where von Zborowski ‘sold’ him the annular wing concept and Östrich agreed to take him on as a consultant.