Leonardo da Vinci’s rotating aerial-screw concept is commonly described as anticipating the helicopter.
Leonardo drew the aerial screw in a manuscript usually dated to about 1489. The design shows a large helical surface mounted on a vertical frame. His accompanying idea was that the screw might rise if rotated rapidly enough, much as a screw advances through a material.
The machine was not a working helicopter. Leonardo lacked a sufficiently light engine and a practical method of producing the required lift and rotation. The drawing is therefore a conceptual ancestor rather than a direct working prototype of a modern rotorcraft.
Modern helicopters use powered rotors to generate lift and control flight, while Leonardo’s aerial screw used a continuous helical surface. The concept is also distinct from his ornithopter, which sought flight through flapping wings. Both designs show Leonardo applying mechanical reasoning to the challenge of human flight.