Heinkel Lerche

The Heinkel Lerche (English: Lark) was the name of a set of project studies made by German aircraft designer Heinkel in 1944 and 1945 for a VTOL fighter and ground-attack aircraft. The Lerche was an early coleopter design. It would take off and land sitting on its tail, flying horizontally like a conventional aircraft. The pilot would lie prone in the nose. It would be powered by two contra-rotating propellers which were contained in a doughnut-shaped, nine-sided annular wing. The design was developed starting 1944 and concluding in March 1945. The aerodynamic principles of an annular wing were basically sound, but the proposal was faced with a host of unsolved manufacture and control problems which would have made the project highly impractical, even without the material shortages of late-war Nazi Germany.

Summary from Wikipedia, photo via Wikimedia Commons, licensed under CC BY-SA.