Leonardo da Vinci designed an ornithopter, a four-winged aircraft modeled partly on insect flight.
Leonardo’s flying-machine studies examined birds, bats, and insects as possible models for human flight. In one design, four wings were connected to a system of rods and pedals so that the operator could attempt to imitate flapping motion. The word ornithopter comes from Greek roots meaning “bird” and “wing,” and it describes an aircraft propelled by flapping wings.
Leonardo understood that human muscle power would be a major limitation. His machines required an operator to move mechanisms, but a person could not generate enough power to sustain the weight of a full aircraft in flight. For that reason, the designs were not successful flying vehicles.
This subject is different from Leonardo’s helical aerial screw and parachute concepts. The ornithopter depends on flapping wings, whereas the aerial screw uses a rotating helical surface and the parachute relies on aerodynamic drag during descent.