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The P.W.S.1 was a design for a two seat reconnaissance fighter that never got past the prototype stage.
The P.W.S.1 was designed in response to a Polish Department of Aeronautics requirement for a fast two-seat reconnaissance fighter to be powered by the 450hp Lorraine-Dietrich W-type engine.
From 1924 to 1926 Podlaska Wytwornia Samolotow (P.W.S.) had concentrated on the production of licence built aircraft, starting with the Potez XVA2 army co-operation aircraft. However in 1926 the company began to produce its own designs, starting with the P.W.S.1.
The new aircraft was designed by Zbyslaw Ciolkosz and Aleksander Grzedzielski. They produced a strut-braced high wing monoplane, using a new aerofoil designed by Prof Czeslaw Witoszynski of the Warsaw Aerodynamic Institute. The wing was a two-spar wooden structure, with constant chord and thickness, and full span ailerons.
In the autumn of 1926 P.W.S. was given a contract to produce one flying prototype and one stress test airframe. The aircraft passed its structural tests in February 1927, and the prototype made its maiden flight on 25 April 1927. The aircraft was then flown to Warsaw to take part in an Aviation Exhibition, but during this flight problems emerged with the untested and experimental wing, which turned out to make the aircraft far too unstable in level flight.
After the end of the exhibition the aircraft was taken back to P.W.S. and rebuilt, becoming the P.S.W.1bis. The main change was the use of a new wing, using the Bobek-Zdaniewski No.4 (Go 648) aerofoil, and an increase in the size of the vertical tail surfaces. The new wing was three feet shorter than the original one, and had a two spar wooden structure with a plywood leading edge and fabric covering. The fuselage had an oval cross section, and was built in two parts, with a steel frame at the front and a wooden frame at the rear. Both parts were fabric covered. The aircraft was armed with two forward firing fixed machine guns and twin Lewis guns in the observer’s cockpit.
The Department of Aeronautics also changed its requirements, and the P.W.S.1 changed from a fast reconnaissance fighter into an army reconnaissance aircraft, with the possibility of it replacing the existing Potez and Breguet biplanes.
The modified aircraft passed its structural tests in 22 October 1927 and began flight tests early in 1928. Its performance was significantly better than with the original wing, but it didn’t offer much of an improvement over the existing aircraft, so no order was placed. However P.W.S. continued to work on the design, producing the P.W.S.19.
Engine: Lorraine-Dietrich twelve-cylinder W-type water cooled engine
Power: 450hp
Crew: 2
Span: 41ft 6.25in (second wing)
Length: 27ft 6in
Height: 10ft 11.5in
Empty Weight: 3,185lb
Normal Loaded Weight: 4,387lb
Maximum Speed: 144.2mph at sea level, 130.4mph at 16,404ft
Cruising Speed:
Climb rate: 3m 25sec to 3,280ft; 13m to 9,842ft
Ceiling: 19,685ft (normal weight), 18,372ft (max loaded weight)
Range: 466 miles
Guns: two forward firing fixed machine guns and twin Lewis guns in the observer’s cockpit