Leonardo da Vinci’s aerial screw is often called a precursor to the modern helicopter.
Leonardo sketched the aerial screw around 1489. Its design used a large helical sail, or screw, intended to rise as the screw rotated. The drawing appears in the Codex Atlanticus, one of the major collections of Leonardo’s surviving notes and diagrams.
The machine was never built and tested by Leonardo, and it could not have flown with the materials and power available in Renaissance Europe. Modern helicopters use powered rotors that generate lift through aerodynamic blades, whereas Leonardo’s concept relied on a fabric-covered helical surface.
The aerial screw is sometimes mistakenly described as the first helicopter. It was not a working helicopter, but its rotating-lift concept made it an important early idea in vertical-flight history. Leonardo also studied bird flight and designed several other flying machines, including ornithopters and parachutes.