Leonardo da Vinci designed an aerial screw as an early concept for vertical flight.
The drawing, usually dated to about 1489, shows a large helical surface wrapped around a central mast. Leonardo proposed that the screw could rise if it rotated rapidly enough, much as a screw advances through a solid material. The design is therefore often described as a distant ancestor of the helicopter.
The aerial screw was not a helicopter and was never built or flown by Leonardo. Its linen-covered framework would have been too heavy, and the proposed human-powered mechanism could not provide enough lift. Modern reconstructions can rotate, but they do not demonstrate practical flight using the original concept.
Leonardo’s idea was important because it separated vertical lift from the flapping-wing approach of his ornithopters. The sketch shows inventive reasoning about air as a medium, even though the necessary engines, lightweight materials, and rotor engineering would not exist for centuries.