The Soko J-20 Kraguj (from Serbian: крагуј, lit. 'sparrowhawk') is a light military, single-engine, low-wing single-seat aircraft with a metal airframe, capable of performing close air support, counterinsurgency (COIN), and reconnaissance missions, that was designed by VTI and manufactured by SOKO of Yugoslavia, first flown in 1962.
Design
It is of classic semi-monocoque, metal structure with a slightly tapered wing. The pilot is accommodated in an enclosed, heated and ventilated cockpit with adjustable seats. The cockpit canopy slides backwards to open. The landing gear is non-retractable with a tail wheel. Rubber dampers provide shock absorption, and hydraulic brakes are used for wheel braking.
The power plant comprises one 340 hp Textron Lycoming GSO-480-B1J6 piston engine and Hartzell HC-B3Z20-1/10151C-5 three-blade metal variable-pitch propeller. The engine cooling airflow is intensified by means of two specially designed ejectors. 36 US Gal of fuel contained in two rubber tanks enables a flight range of 350 NM for the fully armed configuration of the aircraft. 28 V DC electric power is supplied from a 1,5 kW generator and a storage battery. De-fogging and de-icing of the windshield is done by blowing of hot air.
Armament
Permanent armament comprises two wing-mounted 7.7 mm Colt–Browning Mk II machine guns with 650 rounds each and a collimator sight in the cockpit. For combat missions there is a capacity for an external load of bombs and two 57 mm and two 128 mm (HVAR-5) air-to-ground rocket launchers. Adapters on the underwing pylons can be used to switch the armament configuration from free-fall bombs to multi-tube launchers with twelve 57 mm air-to-ground rockets. Cluster, bombs, cargo bombs, and 128 mm air-to-ground rockets can be fitted.
Operation
Drawing on the nation's experience in WWII, Yugoslav military planners assumed that any potential aggressor would disable airfields early in the conflict. The Kraguj was therefore intended to provide a limited reconnaissance-gathering and strike capability to guerilla and insurgent groups in the event of the neutralization of the Yugoslav Air Force, and was referred to as a "Partisan aircraft". It was designed to operate from short, unprepared auxiliary airfields, especially in mountainous regions, and could be fitted with skis. In addition to its primary role as a ground support platform, it was also used as a trainer, both for basic visual day/night flight and for more advanced ground attack training.
