Leonardo da Vinci’s machine with a large helical blade intended to rise through the air was the aerial screw.
Leonardo sketched the aerial screw in the 1480s, most famously in a drawing dated around 1489. The design has a tall, spiral-shaped surface wrapped around a central shaft. Leonardo reasoned that if the spiral were turned quickly enough, it might screw itself upward through the air, in a way resembling a screw moving through wood.
The aerial screw is often called an early helicopter concept, but it was not a functioning helicopter. The sketch does not provide a practical engine, lightweight frame, or sufficiently efficient rotor system. Modern helicopters use rotating blades that generate lift, while Leonardo’s design depended on a continuous helical surface.
The idea is historically important because it shows Leonardo applying mechanical reasoning to flight. It should not be confused with his ornithopter, which attempted to imitate the flapping wings of birds.