Leonardo da Vinci sketched an aerial screw as a helical-rotor flying machine powered by human effort.
He drew the design around 1489, imagining a linen-covered spiral structure that would press against the air and rise. The concept resembles the modern helicopter in its use of a rotating aerial rotor, although Leonardo’s proposed mechanism could not produce enough lift for practical flight.
The aerial screw was not a working aircraft and was never built by Leonardo. Its importance lies in showing that he was thinking about vertical flight centuries before powered helicopters appeared. The drawing is sometimes called Leonardo’s “helicopter,” but that nickname can mislead readers because the machine had no engine, modern rotor controls, or proven flight capability.
Leonardo studied bird flight, air resistance, and mechanical transmission while developing several flying-machine concepts. His aerial screw belongs to this broader body of Renaissance engineering work rather than to a successful aircraft-production program.