The PWS-21 was a Polish passenger aircraft for 4 passengers, built in PWS factory in 1930, that remained a prototype.

Development

The aircraft was developed for a contest for a successor of

Junkers F-13 The Junkers F 13 is the world's first all-metal transport aircraft, designed and produced by the German aircraft manufacturer Junkers. Produced shortly after the end of the First World War, it was a cantilever-wing monoplane with enclosed accom ...

LOT Polish Airlines LOT Polish Airlines, legally Polskie Linie Lotnicze LOT S.A. (, ''flight''), is the flag carrier of Poland. A founding member of IATA, it is one of the world's oldest airlines. With a fleet of 87 aircraft as of June 2025, LOT is Europe's 16th ...

. The first design of 1929, named PWS-21, developed by Stanisław Cywiński and Jarosław Naleszkiewicz, was a braced high-wing plane, but it was not realized because LOT demanded bigger passenger cab. The next design, named PWS-21bis, was a cantilever high-wing plane, similar to Fokker F.VIIa/1m design. The only prototype (markings SP-AEC) first flew in the spring, probably April 1930 in

Biała Podlaska Biała Podlaska (; ) is a city in the Lublin Voivodeship in eastern Poland with 56,498 inhabitants It is the capital of Biała Podlaska County, although the city is not part of the county (it constitutes a separate city county). The city lies on ...

. Its counterpart was Lublin R-XI. The plane appeared not successful. It was too heavy, what resulted in poor speed, ceiling and range, and long take off. In 1931 it was evaluated in LOT airlines, but after a test flight it was returned to the factory. However, at that time there was its development,

PWS-24 The PWS-24 was a Polish single-engine passenger aircraft for 4 passengers, built in PWS (aircraft manufacturer), PWS factory, used from 1933 in aviation, 1933 to 1936 in aviation, 1936 by LOT Polish Airlines. In spite of its limited capacity, it ...

built, sharing the same lightweight wing, which was ordered by LOT.

Description (PWS-21bis)

High-wing cantilever

monoplane A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple wings. A monoplane has inherently the highest efficiency and lowest drag of any wing con ...

of mixed construction, with closed cab and single engine. A fuselage made of a steel frame, covered with

canvas Canvas is an extremely durable Plain weave, plain-woven Cloth, fabric used for making sails, tents, Tent#Marquees and larger tents, marquees, backpacks, Shelter (building), shelters, as a Support (art), support for oil painting and for other ite ...

. Straight one-piece wooden wing, with elliptical endings, plywood covered, two-spar. Crew of two (pilot and mechanic), in a cabin before the wing, with twin controls. The cabin had a vertical front windshield and doors on both sides. Next and slightly below in a fuselage, under the wing, there was a cabin for 4 passengers, with a door on the left. The cabin had a toilet. The fifth passenger could be taken instead of the mechanic. 9 cylinder

radial engine The radial engine is a reciprocating engine, reciprocating type internal combustion engine, internal combustion engine configuration in which the cylinder (engine), cylinders "radiate" outward from a central crankcase like the spokes of a wheel. ...

Skoda

Wright Whirlwind J-5 The Wright R-790 Whirlwind was a series of nine-cylinder air-cooled radial aircraft engines built by Wright Aeronautical Corporation, with a total displacement of about and around . These engines were the earliest members of the Wright Whirlwin ...

(240 hp take-off power, 220 hp nominal power) in the fuselage front, fitted with a

Townend ring A Townend ring is a narrow-chord (aircraft), chord cowling ring fitted around the cylinders of an aircraft radial engine to reduce drag and improve cooling. It was patented in 1929, and found use on various aircraft of the 1930s and into the 1940s ...

. Two-blade metal propeller of a fixed pitch. Conventional

landing gear Landing gear is the undercarriage of an aircraft or spacecraft that is used for taxiing, takeoff or landing. For aircraft, it is generally needed for all three of these. It was also formerly called ''alighting gear'' by some manufacturers, s ...

, with a rear skid; struts with shock absorbers joined the main gear with wings. Fuel tanks 250 L in central wing section.

Specifications (PWS-21bis)

References

External links

Photos and drawings at Ugolok Neba site
{{PWS aircraft 1930s Polish airliners PWS aircraft Single-engined tractor aircraft High-wing aircraft Aircraft first flown in 1930 Aircraft with fixed conventional landing gear

Development

Description (PWS-21bis)

Specifications (PWS-21bis)

See also

References

Further reading

External links