The brothers Otto and Gustav Lilienthal, who came from Anklam in Pomerania in Pomerania, performed considerable preparatory work. Already in the early youth, the two brothers studied the flight of the storks in their Pomeranian homeland. They noticed that the heavy animals always stood against the wind at the beginning of their flight and then risen into the air. They concluded that when blowing on the wing surface there is a suction that ensures the buoyancy of the birds. Otto Lilienthal wrote the knowledge gained through this observation in his book "The Bird Flight as the basis of flying art" in 1889. In 1891 Otto Lilienthal began building flight devices with which he made flight attempts in the Rhinower mountains. In 1893 Otto Lilienthal met 22-year-old Paul Beylich, whose manual skil.
eBay