Leonardo da Vinci’s aerial screw featured a rotating spiral intended to lift a machine into the air.
Leonardo sketched the design around 1489. It shows a large helical surface mounted on a central frame, with people turning cranks to rotate it. His notes suggest that the screw might press against the air and rise in a way resembling a screw moving through a solid material.
The aerial screw is often called an early helicopter, but it could not have flown as drawn. Its proposed human power was insufficient, and the structure lacked the lightweight materials, engine, and rotor controls needed for practical flight. Nevertheless, the idea is historically significant because it recognizes vertical lift through rotary motion. Modern helicopter rotors do not work by copying the whole design, but the sketch remains a famous example of Leonardo’s interest in aviation.