Leonardo da Vinci’s helical machine intended to rise like a helicopter is called the aerial screw.
Leonardo drew the aerial screw around 1489, describing a large spiral rotor made from linen stretched over a reed frame. The machine was meant to be powered by people turning a central mechanism. As the spiral rotated, Leonardo believed it would screw itself upward through the air.
The design is often called a helicopter predecessor because it combines a vertical axis with a rotating lifting surface. However, it was not a helicopter in the modern engineering sense. Its materials, power source, and aerodynamic arrangement would not have produced practical sustained flight.
Leonardo’s sketch is historically important because it shows him exploring vertical flight rather than only birdlike flapping. The aerial screw is also sometimes called the “helicopter” in popular accounts, but “aerial screw” is the more precise name for Leonardo’s design.