PWS-1

PWS-1
Role	Fighter aircraft
Manufacturer	PWS
First flight	25 April 1927
Status	prototype
Primary user	Polish Air Force
Number built	1

The PWS-1 was a Polish two-seat fighter and reconnaissance aircraft, constructed in the PWS in 1927, which remained a prototype.

Design and development

The PWS-1 was the first design of the Podlaska Wytwórnia Samolotów (PWS) - Podlasie Aircraft Factory, and the second aircraft designed and built in Poland, after CWL WZ-X. It was conceived as a single-engine high-wing two-seat fighter, a main purpose of which was escorting of bombers. A design work was carried in 1926 by Zbysław Ciołkosz and Aleksander Grzędzielski, under direction of Stanisław Cywiński.

After static tests, the prototype first flew on 25 April 1927 in Biała Podlaska. Tests revealed poor manoeuvrability, its speed was also low due to a thick wing, despite STOL capability.

In 1928 the plane was reworked, receiving new, lighter, straight wing of thinner profile and duralumin construction instead of wooden, slightly swept one. It also received an enormous vertical stabilizer of rectangular shape with rounded top. After modifications it was flown in early 1929, under a designation PWS-1bis. Its performance improved, but because of a low speed for a fighter, its main purpose was changed to reconnaissance. It was however abandoned, because it had little payload, and in a meantime Poland had bought big parties of better Breguet 19 and Potez 25 reconnaissance and bomber aircraft. In 1929 further works were canceled.

Description

High-wing parasol braced monoplane of mixed construction, with single engine. A fuselage of a steel frame in front and wooden frame in the rear, covered with canvas and duralumin in engine section. Slightly swept wing of wooden construction, plywood and canvas covered, two spar (PWS-1) or straight duralumin wing, of trapezoid-rectangular shape, two-spar, plywood and canvas covered (PWS-1bis). Stabilizers, rudder and elevator of wooden construction, canvas covered. Open pilot's cab, with a windshield, behind it an open observer's cab with two 7.7 mm Lewis machine guns on a ring mounting. Cabs had twin controls. Pilot manned two 7.7 mm Vickers machine guns fixed in a fuselage, with an interrupter gear. Conventional fixed landing gear, with a rear skid.

Engine: 12-cylinder water-cooled inline W12 engine Lorraine-Dietrich LD-12Eb, built in Polish Skoda Works. Water radiator before the engine. Two-blade wooden propeller of a fixed pitch. Fuel tank 375 l in a fuselage front, dropped in emergency.

Specifications (PWS-1bis)

General characteristics

• Crew: 2, pilot and observer
• Length: 8.7 m ()
• Wingspan: 13.7 m ()
• Height: 4.3 m ()
• Wing area: 30 m² (ft²)
• Empty weight: 1113 kg ()
• Loaded weight: 1500 kg ()
• Useful load: 387 kg ()
• Max takeoff weight: 1550 kg ()
• Powerplant: 1 × Lorraine-Dietrich LD-12Eb water-cooled inline W12 engine, 478 hp ()

Performance

• Maximum speed: 232 km/h
• Cruise speed: 200 km/h
• Stall speed: <98 m ()
• Range: 750 km ()
• Service ceiling: 5,600 m ()
• Rate of climb: 5.4 m/s ()
• Wing loading: 65 kg/m² ()

Armament

2 x 7.7 mm Vickers machine guns (pilot's fixed in the fuselage)
2 x 7.7 mm Lewis machine gun (observer's on a ring mounting)

See also

References

• Andrzej Glass: "Polskie konstrukcje lotnicze 1893-1939" (Polish aviation constructions 1893-1939), WKiŁ, Warsaw 1977 (Polish language, no ISBN)

External links

• Photos and drawings at Ugolok Neba