Erhard Brunsmann had built a flapping machine with which short flights were made during 1925. Encouraged by this, he built a sailplane of 44 ft span with a wing area of 130 sq.ft by 1928.
The machine has tapered wings and a usual tail unit, but the main planes are hinged at the centre ao allow up and down movement and are braced by a pair of struts, one to each wing, attaching just behind and below the pilot.
No lateral control was provided, but side movement of the control column actuated the rudder.
The sailplane was first tested as a normal glider, and had similar performance, after which flapping flights were carried out, which increased the speed and about doubled the distance possible with fixed wings.
The machine was being tested at Wasserkuppe in 1931.
All Aero 