Leonardo da Vinci drew an aerial screw as a large rotating spiral flying-machine concept in the 1480s.
The design appears in Leonardo’s notebooks and is commonly regarded as an early idea related to the helicopter. Its helical surface was intended to press against the air and lift the machine when rotated. Leonardo wrote that the device would need a lightweight framework covered with reeds, linen, and sealing material.
The aerial screw was a conceptual machine, not a demonstrated aircraft. The drawing does not provide a complete practical propulsion system capable of producing sustained flight with Renaissance materials. Modern helicopters instead use powered rotors with carefully shaped blades and aerodynamic control systems.
The design is sometimes called a “helicopter” in popular accounts, but that label can be misleading because the modern helicopter did not yet exist. “Aerial screw” is the more specific historical name used for Leonardo’s sketch.