Leonardo da Vinci’s aerial screw was a helical flying-machine concept intended to rise through the air.
Leonardo sketched the aerial screw in the 1480s, most famously in the Codex Atlanticus. The machine featured a large spiral rotor made from reeds, linen, and wire. Leonardo compared its action with a screw moving through a solid material, suggesting that the spiral surface might push against air and lift the structure.
The aerial screw is frequently described as a helicopter predecessor, but it was not a working helicopter. Leonardo’s drawing did not provide a practical engine or a clear method for supplying enough continuous power. The full-size structure would also have been extremely large and heavy for human-powered flight.
Modern helicopters use powered rotors that generate lift through rotating airfoils. Leonardo’s design had a different aerodynamic principle, yet its central idea—vertical flight produced by a rotating system—makes it an important landmark in the history of aviation.