Leonardo da Vinci’s screw-shaped vertical-flight concept was called the aerial screw.
Leonardo drew the aerial screw in a notebook dated about 1489. The design showed a large helical surface wrapped around a central structure, with a frame for people to turn the mechanism. He reasoned that the screw could bite into the air and lift the machine upward, much as an ordinary screw moves through a solid material.
The aerial screw is often described as an early ancestor of the helicopter, but it was not a working helicopter. Leonardo’s proposed materials and human-powered mechanism could not generate enough lift, and the design lacked the modern helicopter’s rotor-control system.
Its historical importance lies in the use of a rotating helical rotor as a flight idea. Centuries later, powered rotors and improved engines made vertical flight practical.