|
|
The P.W.S.10 was the first Polish designed fighter to enter production, but was always intended to be an interim design before the P.Z.L. P.7 could enter service.
The P.W.S.10 was designed in response to a Polish Department of Aeronautics issued late in 1926 for a Polish designed fighter to replace the Spad 51 and Spad 61 biplanes. After examining a range of alternatives P.W.S. put forward a parasol winged monoplane, powered by a Polish built 450hp Lorraine-Dietrich liquid cooled engine, which gained the designation P.W.S.10M (M for Mysliwski or Fighter). At the same time a lighter training version, the P.W.S.11, was developed. The P.W.S.10 used a new aerefoil, the Bobek-Zdaniewski No.3 (Go 647), which was successful tested at Gottingen in October 1927. Early in 1928 a scale model of the design was tested in the wind tunnel at the Warsaw Aerodynamic Institute, and again performed well. However at this point the Department of Aeronautics was more interested in the all-metal P.Z.L. P.1, so no orders were placed.
Over the winter of 1928-29 P.W.S. modified the design. The original plans included a frontal radiator, which was now replaced with an underslung type, located just in front of the fixed undercarriage. The original constant chord wing was replaced with one that had narrower chord and thickness in the centre to improve the pilot’s view. A new steel tube framework replaced the original duralumin tube structure. The fuselage shape was also reworked, only really leaving the parasol wing layout, undercarriage and engine from the original design!
Late in 1929 P.W.S. was given a contract to produce a detailed design of the modified model, and this was followed by a contract to build two prototypes and a static test airframe. By this point the P.Z.L P.1 had carried out its maiden flight, and was performing well, but the Air Force wanted it converted to use radial engines, and work was underway on the P.Z.L. P.7. This also made its maiden flight late in 1929, but some work was still needed before it would be ready to be ordered into production, so the P.W.S.10 was ordered as a back-up.
The P.W.S.10M made its maiden flight in May 1930. Trials throughout the rest of the year found the aircraft to be acceptable but not outstanding, with lower performance than the P.Z.L. P.1, acceptable handling but poor range. However it was ready to enter production, while the P.Z.L.7 was still some way off, so a contract was placed for eighty production aircraft. The first of these was completed in the second half of 1931 and the entire order was completed by the summer of 1932, well before the P.Z.L. P.7 began to enter service.
The production version of the P.W.S.10 had a two spar wing with a wooden structure, plywood and fabric covering to the second spar and fabric only behind the second spar. The wing panels were elliptical in shape, with ailerons along most of the trailing edge. The fuselage was built around a welded steel tube structure, with wooden formers and stringers used to give it an oval cross section. The area in front of the pilot was covered with duralumin, the rest was fabric covered. It was armed with two fixed forward firing machine guns which were carried in the lower part of the fuselage. Power was provided by a 450hp Lorraine-Dietrich twelve-cylinder W-type water cooled engine, with three banks of four cylinders. Each bank protruded from the otherwise neatly streamlined nose, and had to be covered with its own fairing.
The P.W.S.10 was used to fully equip the fighter units of the 3rd (Poznan) and 4th (Torun) Air Regiments early in 1932. Some also went to the 5th (Lida) Air Regiment. However the type had a short front line service life in Poland, and was replaced by the P.7 during 1933. The P.W.S.10s were moved to training units where they became operational fighter trainers.
After the outbreak of the Spanish Civil War fifteen P.W.S.10s were reconditioned and sold to Franco, just before the Polish declaration of neutrality on 29 July 1936. Despite this the aircraft were still delivered, and reached the fascist rebels on December 1936. However despite Franco’s shortage of aircraft, the P.W.S.10 wasn’t suitable for front line service and instead they were used as fighter trainers, before being withdrawn from service in 1938.
The remaining Polish aircraft were still in use at the Delbin training centre at the outbreak of the Second World War, and several were captured intact by the Germans.
In 1930 one of the production aircraft was converted into a biplane, as the P.W.S.15. This performed better than the P.W.S.10, but the company kept it secret at the time, possibly because they were afraid that the Department of Aeronautics would cancel the existing order for the P.W.S.10 and not replace it with one for the P.W.S.15.
Engine: Lorraine-Dietrich twelve-cylinder W-type water cooled engine
Power: 450hp
Crew: 1
Span: 36ft 1.25in
Length: 24ft 7.5in
Height: 9ft 10.5in
Empty Weight: 2,458lb
Normal Loaded Weight: 3,306lb
Maximum Loaded Weight: 3,417lb
Maximum Speed: 160.4mph at sea level
Cruising Speed:
Climb rate: 5min 40sec to 9,842ft
Ceiling: 21,325ft (service), 24,606ft (absolute)
Range: 186.4 miles
Guns: Two fixed forward firing machine guns
Bomb load: