During September 1929, the first prototype conducted its maiden flight. The aircraft demonstrated its outstanding performance amongst its peers, including the British Bristol Bulldog and the French Dewoitine D.27, when it achieved first place at an international air competition held in Bucharest, Romania. The design generated interest around the world; attention was such that the general layout became commonly known as the "Polish wing" or "Puławski wing". This wing consisted of a two-spar duralumin structure, complete with rivetted ribs to both the spars and skin; the exterior of the wing was covered by finely corrugated duralumin sheet, while the slotted ailerons had a fabric covering.