P.W.S. 15

The shortcomings in handling qualities and manoeuvrability demonstrated by the P.W.S.10 prototypes led its designers, Grzedzielski and Bobek-Zdaniewski, in 1930 to develop a biplane version, the P.W.S.15, as a private venture for comparative testing. One of the two P.W.S.10 prototypes was fitted with a modestly staggered unequal-span single-bay biplane cellule with N-type interplane struts. Retaining the engine and armament of the P.W.S.10, the P.W.S.15 lacked the shortcomings of the parasol monoplane, possessing a superior climb rate and an essentially similar maximum speed. However, while the P.W.S.15 was under test, the company received a production contract for the P.W.S.10, and, rather than risk its cancellation in favour of the biplane with consequent production disruption, dismantled the prototype biplane without submitting it to official flight test.