Designated Type 522, the prototype, with s/n 60002, was flown for the first time by Colonel Mihajlo Grbic on June 19, 1955. It was powered by a Wasp radial engine. The type was ordered in mass production and in early 1957 the production of 112 examples for the Yugoslav AF (s/n 60101 to 60212) was started in the new factory of Soko at Mostar (Ikarus had ceased aircraft production). The first was delivered to the air force school on April 23, 1958. In 1978 the type was withdrawn from use, several were stored, a few were put on display at Yugoslav museums, and a handful were exported.
The pictured aircraft, ex Yugoslav AF s/n 60210, was obtained by the renowned French collector Jean Baptiste Salis, in exchange for a Harvard IIB (ex French AF s/n 01289, ex USAF s/n 50-1289) and was registered in France as F-AZEQ on June 1, 1988. The French registration was cancelled on February 27, 1990, as "sold abroad". Still wearing its original military livery it came on the FAA register as N210TU on April 29, 1991, and (reportedly the only flyable one in the USA) still is registered as of this day, although wearing another livery.
Type: Two-seat Advanced Trainer.
Wings: Low-wing cantilever monoplane. All-metal two-spar stressed-skin structure.
Fuselage: Oval section all-metal structure in two sections, forward section of a girder type, rear section a semi-monocoque.
Tail unit: Cantilever monoplane type.
Landing gear: Tail wheel type. Main wheels retract forward into fairings at the wing roots. Hydraulic retraction. Hydraulic wheel brakes. Non-retracting tail wheel.
Power plant: One 600 hp Pratt & Whitney R-1340 AN-1 Wasp nine-cylinder air-cooled radial engine.
Accommodation: Tandem seats under a continuous canopy with sliding sections over each cockpit.
Armament: Two 0.311 in (7.9 mm) MG-15 machine guns and four 55 lb (25 kg) or four 110 lb (50 kg) bombs. There was also provision for two 5 in (12.7 cm) HVAR-5 rockets."
