PWS-4
The PWS-4 (PWS - Podlaska Wytwórnia Samolotów - Podlasie Aircraft Factory) was a prototype Polish sports aircraft, developed in 1928 by Podlaska Wytwórnia Samolotów.
PWS-4 | |
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PWS-4 in 1928 | |
Role | Sports aircraft |
Manufacturer | Podlaska Wytwórnia Samolotów (PWS) |
First flight | September 1928 |
Status | prototype |
Number built | 1 |
Design and development
The PWS-4 was conceived as a cheap and simple single seater sports aircraft. It was designed by August Bobek-Zdaniewski in the Podlaska Wytwórnia Samolotów factory in 1928. The prototype was flown in September 1928 at Biała Podlaska, by Franciszek Rutkowski. It did not enter production due to lack of orders, as the Polish sports aviation movement was interested mostly in more universal two-seater machines.[1] The design was later used as the basis for the PWS-50.
Operational history
The prototype PWS-4 took part in the second Polish Light Aircraft Contest between 29 October-1 November 1928, taking sixth place. Later it was used by the LOPP paramilitary organization in Biała Podlaska. Among others, it was used for aerobatics.[1]
Construction
The PWS-4 was a single-seater high-wing braced monoplane of wooden construction. The fuselage was a wooden frame, covered with plywood, apart from the engine section, which was covered with aluminium sheeting. The empennage structure was wood, with fabric covering. The rectangular wooden wings had two spars; were covered with plywood in front and fabric in the rear; and were supported with pairs of twin struts. The undercarriage consisted of a fixed common axle conventional landing gear, with a rear skid. Fuel was carried in a tank in the wings, 45 l capacity.[1]
The 9-cylinder Salmson AD.9 air-cooled radial engine was rated at 40 hp (30 kW), driving a two-blade fixed pitch wooden propeller. Cruise fuel consumption was 11-13 l/h.[1]
Specification (PWS-4)
Data from Glass, A. (1977), p.180
General characteristics
- Crew: 1
- Length: 5.57 m ()
- Wingspan: 7.6 m ()
- Height: 1.8 m ()
- Wing area: 11 m2 (ft2)
- Empty weight: 238 kg ()
- Useful load: 112 kg ()
- Loaded weight: 350 kg ()
- Powerplant: 1 × Salmson AD.9 air-cooled 9-cylinder radial 2 blade fixed pitch, 40 hp (30 kW) ()
Performance
- Maximum speed: 140 km/h
- Cruise speed: 123 km/h
- Stall speed: 60 km/h ()
- Range: 400 km ()
- Service ceiling: 1350 m ()
- Rate of climb: 1.4 m/s ()
- Wing loading: 38 kg/m2 ()
Notes
- Glass, A., op.cit.
See also
References
- Glass, Andrzej (1977). Polskie konstrukcje lotnicze 1893-1939 [Polish aviation designs 1893-1939] (in Polish). Warsaw: WKiŁ. pp. 179–180.