Leonardo da Vinci’s rotating spiral flying-machine design was called the aerial screw.
Leonardo sketched the aerial screw in the Codex Atlanticus around 1489. Its design featured a helical linen surface, supported by reeds and reinforced with wire, which was intended to rotate around a central shaft. Leonardo reasoned that the spiral surface could “screw” upward through the air, much as a screw moves through a solid material.
The aerial screw is often described as a helicopter ancestor, but it was never built or tested by Leonardo. Its proposed lifting method would have required human muscle power that was far beyond what a practical machine could provide. Modern helicopters use powered rotors and aerodynamic lift rather than a fabric spiral.
The sketch is important because it shows Leonardo thinking about vertical flight centuries before powered helicopters existed. It should not be confused with his parachute, which was intended to slow a descent rather than create powered upward flight.