Leonardo da Vinci sketched an aerial screw with a helical screw and a linen-covered frame.
The drawing appears in one of Leonardo’s notebooks from the 15th century. It shows a large spiral structure intended to press against the air and rise, an idea often compared with the rotor of a modern helicopter. The frame was designed to be covered with a lightweight material, commonly described as linen stiffened with starch.
Leonardo’s concept was not a working helicopter. The proposed machine lacked a practical power source and would have been extremely difficult for its operators to turn. Its importance lies in the recognition that a rotating helical surface might generate lift.
People often call it a helicopter, but “aerial screw” is the more precise historical name. Modern helicopters use powered rotors with aerodynamic blades, control systems, and engines—features absent from Leonardo’s sketch.