Leonardo da Vinci designed an aerial screw, a rotating-air device with a helical sail intended to lift a machine from the ground.
His 1489 drawing shows a large spiral structure made from reeds, linen, and wire. Leonardo reasoned that the helical surface could “screw” upward through the air if rotated rapidly. The concept is often described as an early ancestor of the helicopter, although it lacked an engine and a workable method for producing enough power.
The aerial screw is commonly called Leonardo’s helicopter, but that label can mislead. Modern helicopters use powered rotors that generate lift through aerodynamic blades, while Leonardo’s design relied on a continuous spiral surface. Its historical importance lies in identifying vertical flight as a mechanical problem centuries before powered aviation became possible.