PWS-14
The PWS-12 was a biplane trainer designed and developed by Podlaska Wytwórnia Samolotów (PWS). It entered production as the PWS-14.
| PWS-12 and PWS-14 | |
|---|---|
 | |
| PWS-12bis after modifications | |
| Role | Trainer biplane |
| National origin | Poland |
| Manufacturer | PWS |
| First flight | November 1929 |
| Primary user | Polish Air Force |
| Number built | 23 |
Development
The PWS-12 was a single-engined two-seat training biplane, fit also for aerobatics, designed in 1928 by A. Grzędzielewski and August Bobek-Zdaniewski at the PWS factory. The design shared similar parts, including fuselage and engine, as a high-wing trainer fighter plane PWS-11, developed at the same time.[1] The main difference was the addition of a lower wing. It was powered by a nose-mounted Skoda-built version of the Wright J-5 Whirlwind radial engine. Two prototypes and an airframe for static tests were ordered by the Aviation Department of the War Ministry in February 1928 (along with the PWS-11 prototypes). The first prototype was flown by Franciszek Rutkowski in November 1929. It was later improved - among others, a Townend ring replaced NACA cowling, and it was fitted with N-shaped struts between wings instead of perpendicular struts.[1] The second improved prototype was flown on 18 November 1930, and designated PWS-12bis.[1] Testing was successful and a production order for 20 aircraft was placed by the Polish Air Force.
In a meantime, the factory developed improved model PWS-14, featuring a change from wooden to a steel-tube fuselage, strengthened wings and other improvements, like a door in first cockpit's side. The War Ministry ordered a production of one PWS-14 and a similar modification of the series being in production. It caused some financial problems for the factory, since a production of PWS-12s had already started. As a result, the factory delivered in 1932 a series of 20 PWS-14, marked officially as PWS-12 (military numbers 57.1 - 57.20).[1] A further development of PWS-14 was PWS-16, and then PWS-26.
Operational service
The PWS-14s, officially marked as PWS-12s, were used by the Polish Air Force from 1933 in the Officer Training Centre in Dęblin and a Flying School in Grudziądz.[1] Most were next replaced by the PWS-16 and PWS-26, some remained in use until World War II in 1939.
The second prototype PWS-12bis (factory no. 358) was modified in 1931 to a role of an aerobatics aircraft. Among others, fuselage sides were made flat and a rudder shape was changed.[1] It received markings SP-AKE and was flown mainly by Lt. J. Orłowski. In March 1931 it was used in a trip to Estonia, and in April 1933 - to Romania, Bulgaria, Yugoslavia, Austria and Czechoslovakia. Then, both prototypes were used for several years as utility aircraft in Aviation Technical Research Institute (ITBL). They were later stored in Dęblin.[1]
Variants
- PWS-12
- Prototype of wooden construction.
- PWS-12bis
- Second improved prototype
- PWS-14
- Improved model of mixed construction (aircraft delivered to the Air Force were marked as PWS-12)
Specifications (PWS-14)
Data from Glass, A. (1977)
General characteristics
- Crew: 1
- Capacity: 1 (Trainee)
- Length: 6.9 m (22 ft 8 in)
- Wingspan: 9.0 m (29 ft 6.25 in)
- Height: 2.85 m (9 ft 4 in)
- Wing area: 25 m2 (270 sq ft)
- Empty weight: 775 kg (1,709 lb)
- Gross weight: 1,100 kg (2,425 lb)
- Powerplant: 1 × Skoda-Wright J-5A Whirlwind radial engine , 164 kW (220 hp)
Performance
- Maximum speed: 190 km/h (118 mph, 103 kn)
- Cruise speed: 175 km/h (109 mph, 94 kn)
- Range: 640 km (400 mi, 350 nmi)
- Service ceiling: 4,500 m (14,800 ft)
- Rate of climb: 4.3 m/s (850 ft/min)
References
- Glass, A. (1977)
- Glass, Andrzej (1977). Polskie konstrukcje lotnicze 1893-1939 [Polish aviation designs 1893-1939] (in Polish). Warsaw: WKiŁ. pp. 194–197.
- Taylor, Michael J. H. (1989). Jane's Encyclopedia of Aviation. London: Studio Editions.
- The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985). Orbis Publishing.