Leonardo da Vinci’s rotating device often described as a helicopter precursor was the aerial screw. His drawing shows a large helical rotor intended to push against the air and lift a craft upward.
Leonardo sketched the aerial screw around 1489. The design used a linen-covered helical structure supported by reeds, with a platform and rotating mechanism beneath it. Leonardo reasoned that if the screw could rotate rapidly enough, it might rise through the air in the same way that a screw advances through a material.
The idea was highly innovative, but the proposed human-powered mechanism could not generate the power needed for flight. Modern helicopters rely on powered rotors, lightweight materials, and carefully shaped blades, all unavailable to Leonardo. The aerial screw therefore remained a concept rather than a working aircraft.
It is often called a helicopter precursor, not an actual helicopter. Leonardo’s design had a rotating helical surface, whereas modern helicopters use rotor blades that generate lift through aerodynamic motion.