Leonardo da Vinci studied a glider concept using rigid wings and a human pilot.
His bird-inspired flying studies included a winged machine in which the pilot lay face down and controlled large wings. Leonardo investigated wing shapes, bird anatomy, balance and the effect of air currents. These observations helped him reason about flight even though no powered aircraft was available.
The glider concept differs from Leonardo’s ornithopter studies, which depended on flapping wings. A glider gains lift from forward motion through the air rather than by repeatedly beating its wings. Leonardo’s proposed machine was not proven to fly and would have been difficult to control with the materials and understanding of the period.
Leonardo produced many airborne designs, including parachutes and the aerial screw. They were exploratory studies, not a single completed aircraft program. His importance lies in treating flight as a problem of anatomy, mechanics and aerodynamics.