Leonardo da Vinci sketched an aerial screw, a rotating device often described as a conceptual precursor to the helicopter.
The drawing appears in Leonardo’s collection of engineering studies from the late fifteenth century. It shows a large helical surface wrapped around a central frame. Leonardo reasoned that, if the screw could rotate rapidly enough, its spiral surface might press against the air and lift the structure upward.
The aerial screw was not a working helicopter. Leonardo did not have an engine capable of supplying the necessary power, and the proposed structure would have been heavy. Modern helicopters use powered rotors with carefully shaped blades, while Leonardo’s idea was closer to a rotating screw or spiral airfoil.
The design is historically important because it demonstrates Leonardo’s attempt to reason about vertical flight centuries before powered helicopters became practical. It should not be confused with his flapping-wing aircraft studies, which relied on birdlike motion rather than rotation.