The P.W.S.15 was a biplane version of the P.S.W.10 parasol fighter, but despite having superior performance it was never submitted for official examination, and the sole example was soon converted back into a P.S.W.10.
The P.W.S.10 was a parasol wing fighter that was designed in response to a Polish Department of Aeronautics specification of late 1926. It was never seen as being quite as promising as the more advanced gull wing P.Z.L. P.1, but it was ordered into production to fill a gap before the radial engined P.Z.L. P.7 was ready, with 80 production aircraft delivered between late 1931 and the summer of 1932. The P.W.S.10 had acceptable handling and speed, but poor range.
In 1930 the P.W.S. design team decided to produce a biplane version of the P.W.S.10, which they gave the factory designation of P.W.S.15. This was produced by giving one of the first P.W.S.10s new staggered biplane wings, with an undivided top wing. Steel tube N interplane struts were used. The rest of the aircraft was left almost unchanged.
The P.W.S.15 performed well in private manufacturer’s trials, with better manoeuvrability, climb rate and service ceiling than the P.W.S.10 and almost the same top speed. However the single prototype was them immediately returned to the P.W.S.10 configuration, and it’s existence was never reported to the Department of Aeronautics. The exact reason for this is unclear, although given that in a couple of years time Lublin would be fined for carrying out experiments on one of the Lublin R-XIIIs it is clear that the department had a hostile attitude to unauthorised experiments. The P.W.S.15 was also under development just as the company was preparing for mass production of the P.W.S.10, so it is possible that they didn’t want to risk having that order cancelled in favour of a potentially superior aircraft, only to have the second contract cancelled in favour of a P.Z.L. design. Something similar did happen to P.W.S. a couple of years later when an order for the P.W.S.12 trainer was replaced by one for the more advanced P.W.S.14, but that second type did indeed enter production.
Engine: Lorraine-Dietrich twelve-cylinder W-type water cooled engine
Span: 32ft 9.75in
Length: 24ft 7.5in
Height: 9ft 10.5in
Empty Weight: 2,315lb
Loaded Weight: 3,130lb