Leonardo da Vinci studied ornithopters, aircraft intended to fly by flapping wings like birds.
His notebooks contain extensive observations of bird anatomy, wing shapes, air currents, and the mechanics of flight. He proposed machines in which a human might operate wings through pedals, cranks, or other mechanical linkages. The term ornithopter comes from Greek roots meaning bird and wing, and it describes the aircraft category rather than one single Leonardo model.
Leonardo understood that simply copying a bird’s wings would not solve the problem of human flight. He examined how birds balance, turn, and use moving air, and he recognized that human muscles could not provide the same power-to-weight ratio. Some of his later ideas therefore shifted toward gliding and devices with more practical aerodynamic surfaces.
No Leonardo ornithopter achieved powered flight. His work remains important because it combined direct observation with mechanical experimentation and helped establish questions later studied by aviation engineers.