LWD Junak

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LWD/WSK Junak

Junak 3

Type Trainer aircraft
Manufacturer WSK-Okęcie
Designed by LWD bureau (Tadeusz Sołtyk)
Maiden flight 22 February 1948
Introduced 1952
Retired 1972
Primary user Polish military and civilian aviation
Produced 1951-1956
Number built 252
Variants LWD Zuch

The Junak is a Polish trainer aircraft, used from 1952 to 1961 by the Polish Air Force and to 1972 by a Polish civilian aviation, designed in the LWD bureau and produced in the WSK factory.

Contents

[edit] Design and development

The aircraft was designed in response to a Polish Air Force requirement of 1946 for a trainer plane to replace the Soviet UT-2, which was obsolete and difficult to handle aircraft. The new plane was designed in 1947 in the LWD (Lotnicze Warsztaty Doświadczalne - Aircraft Experimental Workshops) - the first Polish post-war construction bureau. The chief designer was Tadeusz Sołtyk. A prototype named LWD Junak, later Junak 1 was flown on February 22, 1948 (name meaning "brave young man", old-fashioned). A whole design was Polish, except for an engine, which was licence-built Soviet radial Shvetsov M-11D (93 kW, 125 hp).

After tests, an improved variant Junak 2 was flown on July 12, 1949. The most notable changes from the Junak 1 were: crew cab moved towards front, bigger tailfin, stronger M-11FR engine (118 kW, 160 hp) and lack of massive landing gear covers. The plane's handling improved. In a meantime, the LWD team was disbanded in 1950 and the Junak 2 was further developed by the CSS workshops in Warsaw. After some improvements the prototype was designated Junak-2bis, but finally entered production in 1951 as Junak-2. Tadeusz Sołtyk was given a State Award in 1952 for the design. From 1951 to 1954, 105 Junak 2s were produced in the WSK-Okęcie in Warsaw (the first 3 in the WSK-Mielec).

Tadeusz Sołtyk, then working in the Aviation Institute (Instytut Lotnictwa - IL) in Warsaw, proposed next a Junak development with bubble canopy, retractable landing gear and other improvements, designated TS-7 Chwat, but it was not accepted by the authorities and remained in sketches. Instead, after the Polish Air Force was equipped with first jet fighters (Yak-23, MiG-15), there appeared a need of a trainer plane with a tricycle landing gear. Then, Sołtyk designed a modified Junak with a fixed tricycle landing gear and minor improvements. This plane was accepted for a production as TS-9 Junak 3 ("TS" for Tadeusz Sołtyk). It was first flown on August 7, 1953. The new plane was heavier, and the maximum speed was reduced from 223 km/h (139 mph) to 205 km/h (128 mph). Between 1953 and 1956, 146 Junak 3s were produced in WSK Warszawa-Okęcie.

Along with the Junak 1, the LWD developed its civilian trainer and aerobatics variant LWD Zuch. Only a short series of 5 Zuch 2s was built in 1950, powered with the 116 hp Bramo Sh 14 radial engine.

The Junak was the first aircraft built in a big series in Poland after the World War II, which annihilated the Polish aviation industry. Despite not very modern, it was a stable and good handling aircraft, one of its few flaws was uncomfortable cab. All models of Junak are often called LWD Junak or WSK Junak, a designation TS-9 is not commonly used. There happen also in books a designation IL Junak 3.

[edit] Operational history

Junak-3 in the Polish Aviation Museum
Junak-3 in the Polish Aviation Museum

Junak 2s were used in the Polish Air Force as a basic trainer from 1952. When their replacement with Junak 3s started in 1954-1955, Junak 2s were withdrawn from the Air Force and handed over to civilian aviation (aero clubs).

Junak 3s were used in the Polish military aviation from 1954 until 1961, when they were finally replaced with TS-8 Bies. Starting from 1956, they were handed over to civilian aviation as well.

In the civilian aviation, 71 Junak 2s and 93 Junak 3s were distributed among aero clubs in the country, suffering lack of aircraft after the war. They were used there for pilots' training and glider towing through the 1960s. The last Junak 2s and Junak 3s ended service in 1972.

[edit] Variants

Junak 1
Prototype.
Junak 2
First serial produced variant, 105 aircraft built.
TS-9 Junak 3
Fixed tricycle landing gear version, 146 aircraft built.

[edit] Operators

Flag of Poland Poland

[edit] Survivors

Junak-1 (SP-GLA)
Preserved in the Polish Aviation Museum in Kraków (damaged and disassembled as of 2008).
Junak-2 (SP-ADM)
Preserved in the Polish Aviation Museum in Kraków (disassembled as of 2008).
Junak-3 (SP-BPL)
Preserved in the Polish Aviation Museum in Kraków.

[edit] Specifications (Junak 3)

[edit] Description

Junak 3 in the Polish Aviation Museum in Kraków
Junak 3 in the Polish Aviation Museum in Kraków

Mixed construction (steel and wood) trainer plane, conventional in layout, a low-wing monoplane. Fuselage of steel frame, covered with canvas, in front with metal sheet. Two-spar wings of wooden construction and trapezoid shape, canvas and plywood covered, fitted with split flaps. Two-seat cabin (front: instructor, rear: student) with a common closed canopy (front section opening to the right, rear section sliding). Conventional (Junak 2) or tricycle (Junak 3) fixed landing gear. 5 cylinder radial engine M-11FR with 119 kW (160 hp) maximum power and 104 kW (140 hp) normal power. Cylinders have individual cowls, often removed. Two-blade fixed pitch wooden propeller. Fuel: 80 l (Junak 2) or 100 l (Junak 3). The plane had no armament. Junak 3 was fitted with radio.

General characteristics

  • Crew: two - student and instructor
  • Length: 7.75 m (25 ft 5 in)
  • Wingspan: 9.92 m (32 ft 6 in)
  • Height: 2.5 m (8 ft 2 in)
  • Wing area: 17.50 m² (188 ft²)
  • Empty weight: 818 kg (1,800 lb)
  • Loaded weight: 1,080 kg (2,376 lb)
  • Powerplant:Shvetsov M-11FR air-cooled 5-cylinder radial engine, 160 hp (118 kW)

Performance

[edit] See also

Related development

Comparable aircraft

[edit] References

  • Kempski, Benedykt. Samolot szkolno-treningowy Junak, TBiU #110, Wydawnictwo MON, Warsaw 1986, ISBN 83-11-07341-4 (Polish) (main reference)
  • Krzyżan, Marian. Samoloty w muzeach polskich, Wydawnictwo WKiŁ, Warsaw 1983, ISBN 83-206-0432 (Polish)

[edit] External links


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