LWD Junak

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LWD Junak

Junak 3
Type	Trainer aircraft
Manufacturer	WSK-Okęcie
Maiden flight	1948-02-22
Introduced	1952
Retired	1972
Primary user	Polish military and civilian aviation
Produced	1951-1956
Number built	252

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 by the LWD team and produced in the WSK factory.

1 Development
2 Usage
3 Description
4 Specifications (Junak 3)
5 Operators
6 Related content

[edit] 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 Doswiadczalne - Experimental Aviation Workshops) - the first Polish post-war construction team. The main designer was Tadeusz Sołtyk. A prototype named LWD Junak, then Junak 1 was flown on February 22, 1948. 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 and put to a production in 1951. The most notable changes from the Junak 1 were: crew cab moved towards front, bigger tailfin and stronger M-11FR engine (118 kW, 160 hp). In a meantime, the LWD team was disbanded in 1949 and the Junak 2 was further developed by the CSS workshops in Warsaw. From 1951 to 1954, 105 Junak 2s were produced in the WSK-Okęcie in Warsaw (the first 3 in the WSK-Mielec).

Tadeusz Sołtyk, working in the Aviation Institute (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 Soltyk). 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.

Along with the Junak 1, the LWD developed its civilian trainer-aerobatic variant LWD Zuch 1 with Walter Minor 6-III inline engine (119 kW, 160 hp), flown in 1948, then the LWD Zuch 2 with the Bramo Sh 14 (116 hp) radial engine. Only a short series of 5 Zuch 2s was built in 1950 and used until 1955.

[edit] Usage

Junak 2s were used in the Polish military trainer aviation from 1952. When their replacement with Junak 3s started in 1954-55, Junak 2s were withdrawn from the Air Force and given to civilian aviation. 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 given 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 training and glider towing through the 1960s. The last Junak 2s and Junak 3s ended service in 1972.

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.

[edit] Description

Mixed construction (steel and wood) trainer plane, conventional in layout, with low-wings. 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. 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. The plane had no armament. Junak 3 was fitted with radio.

[edit] Specifications (Junak 3)

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: 1× Shvetsov M-11FR air-cooled 7-cylinder radial engine, 160 hp (118 kW)