The innovative processes that were linked to the change from biplane to monoplane reached the Yugoslavian aeronautical industry, traditionally considered second-rate compared to those of the major European powers, in the first half of the 1930s. The result of this was the Rogozarski IK-3, a small, agile fighter with enclosed cockpit and all retractable landing gear, which proved to be just as reliable and rather more easy to handle than its two more illustrious contemporaries, the British Hawker Hurricane and the German Messerschmitt Bf 109. However, the IK-3 had a relatively short life span, dictated by the events of the war itself. The production program came to a halt when the Germans invaded, by which time only 12 aircraft had been delivered to the units.

In 1933, the idea of developing a modern combat plane came to Ljubomir Ilic and Kosta Sivcev the two technicians who had produced the first entirely Yugoslavian fighter, the IK-1, a couple of years earlier. Encouraged by this experience, the two designers, along with Slobodan Zrnic were convinced that the era of the biplane and the high-wing monoplane was over and that, considering the high-quality performance of the new bombers being developed at the time, only a low-wing monoplane with retractable landing gear possessed the characteristics necessary to guarantee supremacy in the air. The project got under way in great secrecy, and toward mid 1936 all drawings and documentation were handed over to the military authorities for examination.

However, the initial evaluation phase proved to be long, the delay caused to a great extent by official scepticism concerning the new formula. Not until March of the following year was a contract signed for the production of a prototype. The factory that was to supervise its construction was Rogozarski, based in Belgrade. The first aircraft was completed a year later, and the IK-3 made its maiden flight near the end of May 1938. The fuselage had a steel tube airframe with a mixed canvas and metal covering, and the wing was built almost entirely of wood, with only a few steel tube reinforcements. The prototype was powered by a 910 hp (679 kW) "V-12" Hispano-Suiza 12 Y29 engine with supercharger (although in the production series this was replaced by the equally powerful 12 Ycrs model built by Avia on license), which drove a three-bladed variable pitch metal propeller. The armament consisted of a 20 mm cannon installed on the propeller shaft and two fixed machine guns in the fuselage.

During evaluation tests, the concentration of the armament in the nose was one of the most appreciated features, although the aircraft's maneuverability and excellent overall performance also made a good impression. However, flight tests were interrupted suddenly on 19 January 1939, when the prototype crashed to the ground following a deep dive, causing the death of the test pilot, Milan Pokorni. Even though the causes of the accident were not attributed to serious structural problems, this event delayed still further the start of production, which had been planned on the basis of an order for 12 aircraft barely three months earlier.

The first six aircraft were delivered in March 1939, and the others by July. The IK-3s equipped the 161 and 162 Eskadrila, which formed part of the 51st grupa based at Zemum airfield. Beginning on April 6, 1941, the date of the German invasion of Yugoslavia, the twelve operational IK-3s proved their worth in the fierce fighting against the Luftwaffe, destroying eleven enemy aircraft before last two surviving aircraft were destroyed at the emergency strip at Veliki Radnici by their crews during the night of April 11/12. At that time, another 25 aircraft were under construction.

Specifications (Rogozarsky IK-3)

Type: Single Seat Fighter

Design: Ljubomir Ilic, Kosta Sivcev and Slobodan Zrnic

Manufacturer: Prva Srpska Fabrika Aviona Zivojin Rogozarsky in Belgrade

Powerplant: One 960 hp (716 kW) Avia built Hispano-Suiza 12Ycrs moteur canon engine.

Performance: Maximum speed 327 mph (527 km/h); service ceiling 30,840 ft (9400 m).

Range: 488 miles (785 km) on internal fuel.

Weight: Empty equipped 4,559 lbs (2068 kg) with a maximum take-off weight of 5,798 lbs (2630 kg).

Dimensions: Span 33 ft 9 1/2 in (10.30 m); length 26 ft 3 in (8.00 m); height 10 ft 8 in (3.25 m); wing area 177.6 sq ft (16.50 sq m).

Armament: One engine mounted 20 mm Oerlikon FF cannon and two fuselage mounted and synchronised 7.92 mm (0.31 in) FN Browning machine-guns.

Variants: Rogozarsky IK-3.

Avionics: None.

History: First flight (prototype) May 1938; first deliveries March 1939; last aircraft destroyed April 1941.