Leonardo da Vinci’s aerial screw used a rotating helical blade to suggest a way to rise into the air.
Leonardo sketched the aerial screw around 1489–1490 in his notebooks. The design showed a large linen-covered spiral resembling a screw, supported by a framework. Leonardo reasoned that if the spiral rotated quickly enough, it might push against the air and lift the structure.
The aerial screw is often described as an early helicopter concept, but it was not a working helicopter. Leonardo had no lightweight engine or practical rotor mechanism capable of producing the necessary lift. Modern helicopters also use rotating blades, but their rotors are shaped and powered very differently.
The drawing is especially important because it shows Leonardo studying flight through mechanical principles rather than merely imitating birds. It is sometimes confused with his parachute, which addressed controlled descent rather than powered ascent.