Leonardo da Vinci’s helical vertical-flight concept was the aerial screw.
Leonardo drew the aerial screw in the 1480s, most famously in a page of the Codex Atlanticus. The machine has a large spiral or helical sail mounted around a central mast. Leonardo proposed that rotating the structure could make it push against the air and lift the machine upward.
The aerial screw is often called an early helicopter concept because it anticipates vertical takeoff and landing. However, it was not a functioning helicopter. The design lacked a practical engine, and its proposed materials and power source would not have supplied enough energy for sustained flight.
Its importance lies in the underlying idea: a rotating helical surface could generate upward motion. Modern helicopters use powered rotor blades, which are aerodynamically and mechanically very different. Leonardo’s sketch is therefore best described as a conceptual precursor, not the first working helicopter.