Leonardo da Vinci’s rotating flight machine was called the aerial screw.
Leonardo sketched the aerial screw around 1489. Its design featured a helical surface wrapped around a vertical frame, intended to push against the air as the machine rotated. The concept is frequently compared with the rotor of a modern helicopter, although it would not have flown under its own power as drawn.
The machine was probably inspired partly by the action of a screw moving through water. Leonardo reasoned that a similar spiral form might climb through air. His notes show that he was investigating lift, resistance, propulsion, and the structure of air decades before aviation became practical.
The aerial screw was not a working helicopter. It lacked a suitable lightweight engine and a reliable way to generate continuous rotation. Nevertheless, it is one of Leonardo’s best-known flight concepts and an important example of his mechanical experimentation.