Leonardo da Vinci designed the aerial screw in 1485 as an early helicopter concept.
His drawing shows a large helical sail made from linen stretched over a reed frame. Leonardo reasoned that, if the screw rotated quickly enough, its spiral surface could rise through the air. The design was probably inspired by the Chinese flying top, a toy known in Europe through illustrations and reports.
The aerial screw was a conceptual machine, not a working helicopter. It had no practical engine capable of turning the rotor, and its heavy frame and fabric would have made flight difficult. Modern reconstructions are useful for demonstrating the idea, but they do not prove that Leonardo’s original design could have flown.
A common mix-up is calling it a helicopter. The modern helicopter depends on powered rotary wings, control systems, and lightweight materials developed centuries later. Leonardo’s aerial screw is better understood as an important historical precursor to vertical-flight thinking.