Leonardo da Vinci sketched an ornithopter, an aircraft intended to fly by flapping wings modeled on birds and bats.
Leonardo studied the anatomy and movement of birds, bats, and insects in hopes of understanding human flight. His proposed flying machines used a pilot’s muscles, levers, pedals, and wing mechanisms to imitate flapping motion. Several drawings survive in his notebooks, including designs with broad wings and articulated joints.
No Leonardo ornithopter was successfully flown, and the machine would not have produced enough lift with human muscle power alone. An ornithopter is different from a glider, which remains airborne through aerodynamic lift without flapping wings. Leonardo’s work nevertheless contributed detailed observations to the long history of aircraft design.