Leonardo da Vinci’s four-winged vertical-lift machine is called the aerial screw.
Leonardo sketched the aerial screw in about 1489, probably in the Codex Atlanticus. Its helical linen-covered rotor was intended to press against the air and raise the entire frame, making it one of the earliest recorded helicopter concepts.
The design was not a working helicopter. Leonardo had no lightweight engine, and the materials available in Renaissance Italy could not provide the power-to-weight ratio needed for flight. The machine also depended on a large rotor and a substantial wooden framework.
The aerial screw is often confused with Leonardo’s ornithopter, which copied the flapping motion of birds. The screw used rotary motion instead. Modern helicopters use powered rotors, but their aerodynamic principles and controls are far more developed than Leonardo’s proposal.