Leonardo da Vinci sketched a helicopter-like flying device as an aerial screw.
Leonardo drew the design around 1489, showing a large helical sail intended to press against the air and lift the machine. The sketch appears in his Paris Manuscript B, where it is associated with studies of flight and mechanical motion.
The design was not a working helicopter and was never built by Leonardo. Its rotating screw concept resembles the basic principle of a modern helicopter rotor, but the proposed machine would have required materials and an engine unavailable in Renaissance Europe. Leonardo imagined four people turning a central mechanism to rotate the screw.
The term helicopter came much later, and historians usually describe Leonardo's device as a precursor or helicopter-like concept rather than the first helicopter. Modern helicopters use powered rotors that generate lift through aerodynamic blades, not a linen-covered spiral surface.