Leonardo da Vinci’s flying-machine design with a large rotating screw is called the aerial screw.
Leonardo drew the aerial screw in the Codex Atlanticus around 1489. The design shows a helical sail made from linen stretched over a reed framework, supported by a circular platform. Leonardo suggested that rotating the screw could make it rise through the air, an idea often compared with the principle of a modern helicopter rotor.
The aerial screw was never built or tested by Leonardo, and the drawing does not provide a complete engine or practical control system. Its importance is conceptual: it shows Leonardo reasoning about lift, rotation, lightweight structures, and human flight centuries before powered helicopters existed.
A common mix-up is calling it a helicopter. “Aerial screw” is the historical name for Leonardo’s design; modern helicopters use powered rotors with aerodynamic blades rather than a fabric-covered helical surface.