Leonardo da Vinci designed an aerial screw with a screw-shaped wooden frame turned by people.
The drawing appears in Leonardo’s notebooks from around 1489. It shows a helical surface covered with reeds and cloth, mounted around a central mast. Leonardo reasoned that if the screw rotated rapidly, it might press against the air and rise. The concept resembles a large rotating screw rather than a modern aircraft rotor.
The aerial screw was never demonstrated as a practical flying machine. Human-powered mechanisms could not provide enough sustained power for the proposed structure, and the design lacked the aerodynamic understanding and lightweight engines needed for powered flight.
Although it is often called an early helicopter, that label is only an analogy. Modern helicopters use powered rotors that generate lift through rotating blades. Leonardo’s sketch was an imaginative exploration of vertical flight, not a functioning helicopter prototype.