Leonardo da Vinci’s helicopter-like design was called the aerial screw.
Leonardo drew the aerial screw in about 1489, probably in his manuscripts on flight. The machine has a large helical surface wrapped around a central mast. Leonardo reasoned that, if the screw rotated quickly enough, its surface could push against the air and lift the structure.
The aerial screw was never built by Leonardo and lacked a practical engine or a demonstrated method of producing enough power. It is therefore best understood as a pioneering flying-machine concept rather than a working helicopter.
The design is often described as a helicopter ancestor, but it did not use the powered rotor system found in modern helicopters. Its broad spiral surface makes it closer to a theoretical air screw.