Otto Lilienthal Normalsegelapparat

The Normalsegelapparat was Otto Lilienthal's standardized monoplane hang-glider design and the first aircraft type built and sold in a small production series. Its folding willow-and-fabric wings and weight-shift control embodied lessons from Lilienthal's systematic aerodynamic research and thousands of glides. Photographs and demonstrations of the design gave late-nineteenth-century audiences visible proof of controlled human flight and directly influenced later experimenters, including the Wright brothers.