The Rhön-Rossitten Gesellschaft (RRG) or Rhön-Rossitten Society was a German gliding organization, the first one in the world that was officially recognised. The Rhön-Rossitten Gesellschaft was mainly responsible for establishing gliding as a sport, not only in Germany but eventually throughout the world. Because the Treaty of Versailles forbade any form of powered flight in Germany, many young pilots and aircraft designers turned to gliding as a sport. Under Oskar Ursinus and Theodore von Kármán, hobbyists and serious university study groups began building gliders. The first contest was held in 1920 on the mountain of the Wasserkuppe in the Rhön region of Hesse. While many of the entering designs were no more than kites and many of the 'flights' were no more than stumbles ending in a crash, Kármán and his team from the RWTH Aachen with their glider Schwarzer Teufel (Black Devil) pioneered the bungee-launching method and regularly managed flights of over a minute followed by a crash-free landing. The event was then repeated annually with a constant improvement in the gliders and the results. Simultaneously another gliding group formed at the Rossitten sand dunes at the Curonian Spit in East Prussia. Although far apart, the enthusiasts from the Wasserkuppe and Rossitten frequently met and compared ideas, designs and techniques. One big organization was suggested to coordinate the activities at the Rhön and the Rossitten dunes, and every other gliding club that might be founded. In 1924, 'Rhönvater' (Rhön father) Oskar Ursinus convinced the then Secretary of Air Transport for the Ministry of Transportation, Dr. Brandenburg, to found a national gliding organization, the Rhön-Rossitten Gesellschaft. From the start, the new society did everything to provide an all-round service to gliding enthusiasts: it organized yearly gliding competitions; it managed flying schools at Rossitten and the Wasserkuppe; it had its own workshops for constructing gliders and its own research team to develop newer and better gliders. There was also a meteorological work group which investigated thermals and ridge-lift. In 1925, Ursinus took yet another bold step by appointing Alexander Lippisch as head of the technical branch of the RRG. Lippisch advanced the work of RRG by designing and building ever more sophisticated gliders. Also in 1925 the ban on powered aircraft was partially lifted and soon the RRG started experimenting with motor gliders. In addition to the 'traditional' way of bungee-launching gliders, the RRG also developed winch launching and aerotowing to