Flight Controls of Otto Lilienthal's Experimental Monoplane from 1895

In 1889, Otto Lilienthal published his book Birdflight as the Basis of Aviation, containing the first lift-versus-drag data of cambered wings and other important information required for human flight. In 1895, Lilienthal demonstrated his 12th aircraft design, a monoplane with a wing area of over 20 m2. Because of its wingspan of almost 9 m and wing chord length of 3 m, Lilienthal’s largest monoplane can only be used in light winds. Lilienthal applied for a patent on the same day. The patent claim was submitted for the front wing (Vorflügel), a leading-edge flap used in a glider for this purpose for the first time. Because of the size of the apparatus, three profile rails were slid onto each wing instead of the usual two