Leonardo da Vinci’s helicopter-like design is known as the aerial screw. It used a large helical structure intended to rise by forcing air downward as it rotated.
Leonardo drew the design around 1489. The sketch shows a spiral sail made from reeds, covered with linen, and supported by a framework. He reasoned that if the helical surface turned rapidly enough, it might screw itself upward through the air. The concept was not a working helicopter, because the proposed human-powered mechanism could not supply enough energy to rotate such a large rotor.
The aerial screw also lacked several features essential to modern helicopters, including a practical engine, rotor-control system, and anti-torque arrangement. Its importance is conceptual: it anticipated vertical-lift thinking rather than providing a directly usable aircraft.
The machine is frequently called a “helicopter” in popular accounts, but “aerial screw” is the more precise name for Leonardo’s drawing. Modern helicopters use rotating blades and powered rotors, not a single linen-covered spiral.