Reports of the first
German glider contest, held at the
Wasserkuppe in the late summer of 1920, generated considerable interest in Poland, leading to the First Polish Glider Contest at
Czarna Góra between 30 August and 13 September 1923. The contest was not a great success, limited by novice designers and pilots and a poor site, but the
Karpiński SL.1 Akar was by far the most successful entrant. The Żabuś was designed for the contest by Captain Franciszek Jach and built in the Pilots' Lower School's workshops at
Bydgoszcz. The wooden glider had a two-part, rectangular plan,
fabric covered parasol wing built around two
spars. Its outer parts carried
washout and had unusual short but broad
chord ailerons which widened to full chord close to the tip. Each aileron was operated independently with its own lever. The wing was held low over the fuselage by a steel tube
cabane and braced centrally with outward-leaning splayed N-struts from the fuselage lower
longerons to the wing spars on each side. Its rectangular section,
plywood-covered fuselage included an open cockpit under the wing and had an unusual profile, like a
cambered airfoil with a strongly arched underside. At the rear there were no vertical surfaces, only a broad chord, triangular
tailplane carrying a one-piece, fabric-covered, foot-operated
elevator. Jach piloted the Żabuś on its only flight and crashed after only 19 seconds, probably because of the unconventional control system. It was rebuilt for the 1925 Second Polish Polish Glider Contest, held at
Oksywie on the
Baltic coast, as the Żabuś 2. After the rebuild the glider had a large, fabric-covered
fin and
rudder of overall trapezoidal profile, with an appropriately altered control system. As well as making several short flights the Żabuś 2, piloted by Władysław Sulczewski, won the straight line distance prize with a flight covering . ==Variants==