What flying-machine type did Leonardo da Vinci sketch with birdlike wings?

Leonardo da Vinci sketched an ornithopter as a flying machine with birdlike wings.

An ornithopter is an aircraft designed to fly by flapping wings, rather than by using fixed wings or a propeller. Leonardo studied birds, bats, and the mechanics of wing movement while developing several flying-machine designs in the late fifteenth and early sixteenth centuries.

His drawings show a human pilot lying or standing inside a frame and operating wings through pedals, levers, or other mechanical parts. The designs were ingenious, but human muscles alone cannot provide enough power for a practical large-scale ornithopter. Leonardo therefore did not build a successful powered aircraft.

The term is sometimes confused with “helicopter,” because both ideas appear in Leonardo’s notebooks. An ornithopter depends on flapping wings; a helicopter depends on rotating blades. Modern ornithopters exist as small experimental aircraft and robotic devices, but Leonardo’s sketches remained conceptual studies.