Leonardo da Vinci’s proposed human-powered flapping-wing aircraft is an ornithopter.
The word ornithopter means a flying machine that gains lift and thrust by flapping wings, broadly imitating birds, bats, or insects. Leonardo studied bird flight extensively and filled notebooks with observations about wing movement, balance, wind, and anatomy. His machine designs included a frame and wings intended to be powered by the pilot’s arms and legs.
None of Leonardo’s ornithopter designs flew. Human muscles cannot provide enough sustained power for a practical flapping aircraft of the proposed size, and the mechanisms would have been too heavy. Leonardo’s work nevertheless helped connect artistic observation with mechanical experimentation. The term applies to the aircraft type, not to one uniquely finalized Leonardo prototype.