During the autumn of 1935, the considerable potential of the
Fieseler Fi 156 project for the tasks of short-range reconnaissance and aerial observation had prompted the
RLM to draw up a requirement for an army cooperation and observation aircraft with its performance parameters. The requirement stipulated the use of the
Argus As 10 or the
Hirth HM 508 engine and placed emphasis on short field performance, maximum possible allround view for the two crew members, and a wide range of speed. It was intended that the resultant aircraft, which the
Siebel Si 201 was also designed to compete for, would be evaluated in competition with the Fi 156. The Bf 163 closely followed the formula established by the Fi 156 by being a high-wing braced
monoplane with a metal structure, automatic leading edge wing slots, double slotted flaps, and an exceptionally tall undercarriage. The aircraft's most interesting feature was the provision for varying the
incidence of the entire wing which swivelled on its mainspar, the bracing struts being attached to the fuselage by ball joints and changing their angle with movement of the wing. Construction of the sole prototype was entrusted to
Weserflug, though due to its origin with the
Bayerische Flugzeugwerke before
mid-July 1938, it retained the
Bf RLM prefix for the earlier firm. ==Operational history==