Rogožarski IK-3

Ikarus Rogozharski IK-3

Creation
In the second half of the 1930s, it was clear to the command of the Yugoslav Royal Air Force that it was necessary to think about modernizing the fighter air force. Although modern foreign designs were available (e.g. the Hurricane), the air force struggled to acquire its own machines. The pair of Rogozarski designers Ljubomir Ilić and Kosta Sivčev, authors of the successful IK-1 and IK-2, set to work in utmost secrecy. Since 1936, the design work has been underway, and the models of the machine have been undergoing tests in the Eiffel wind tunnel in Paris. The engineer Slobodan Zrnić was also involved in the construction. As a result, in March 1937 the Yugoslav Ministry of Aviation awarded the contract to Rogožarski A. D. to build the prototype.

The IK-3 prototype first flew in the spring of 1938. In the cockpit sat captain Nikole Bjelanović. The aircraft was designed as a low-wing single-seat monoplane, powered by a liquid-cooled Hispano-Suiza 12Y-29 inline engine of 920 hp (686 kW), which drove a non-buildable Hispano-Suiza propeller, a Hamilton Standard Constant Speed license production. It also carried one Hispano-Suiza HS-404 20 mm cannon with a magazine of 60 rounds and 2 FN-Browning 7.92 mm machine guns with 500 rounds for each. The cannon was mounted between the engine cylinders and fired through the hollow shaft of the propeller, the machine gun armament was hidden under the hood above the engine and fired through the propeller circuit. The machine received a retractable Messier landing gear.
In order to be as objective as possible, a total of 6 pilots conducted the flight tests. The prototype met its fate on 19 January 1939, when during a test flight the pilot kapetan Milan Pokorni exceeded the speed limit during dive flight while performing aerobatic elements and the aircraft became uncontrollable. After a dive flight from 1 500 m, at an altitude of about 400 m, first the cockpit overlap came loose, then the wing spar broke at the landing gear anchorage. The machine was destroyed on impact with the ground and the pilot was killed. As the ministerial commission investigating the crash found no fault in the design of the machine, 12 serial machines were ordered. 6 were to be delivered by the end of March, the remaining 6 by the end of July 1939.

The construction was mixed, the wing being wooden with metal fittings, the fuselage structure made of steel tubes and finished with wooden structure, the nose with the engine up to the pilot's seat covered with duralumin sheeting, the rear of the fuselage as well as the wing covered with canvas similar to the Hawker Hurricane. Ailerons and control surfaces aluminium, canvas coated. Main and aft landing gear fitted with Dunlop wheels. Also available with retractable aft wheel. Machine No. 2-2151/1 carried a Telefunken FUG VIIa radio with a range of 60 km.

Production
The production machines differed from the prototype in some details. The original French engine was replaced by an Avia H engine produced under license in the Czechoslovakia. S.12Ycrs, the cabin was given a new windshield with bulletproof glass and a rearward sliding overlap. Hamilton Standard propellers were also carried by the first 6 production machines. The second six received Chauviere 351m propellers. The fuel tanks - 1 in the fuselage and 2 in the wings held a total of 330 litres of fuel.

Deliveries began in the summer of 1940 and pilots rated the new machine as agile and easy to fly. Pilots preferred it to the Hawker Hurricane Mk. I and the Messerschmitt Bf 109E-3, which they also flew. They particularly liked its ability to fly very small radius turns. Another batch of 25 machines was ordered and licensed production in Turkey was discussed. With the start of series production, design work focused on further development - this was mainly about the possibility of fitting a more powerful engine. Several alternatives were in play: the new Hispano-Suiza 12Y-51 with 1,100 hp, the Daimler-Benz DB601A, the Rolls-Royce Merlin III with an output of even 1,030 hp. On paper, there was also an IK-5 project with two H.S. 12Y engines. This was even to take two forms - a single-seat fighter or a two-seat long-range heavy fighter with a massive barrel armament concentrated in the nose. Models of the IK-5 were already being tested in the wind tunnel and a prototype was being prepared for production. But the German invasion of Yugoslavia on 6 April changed the situation. The IK-5 remained in the models, and production of the second series of IK-3s was cancelled. For the same reason, licensed production in Turkey was abandoned.

A total of 12 machines + 1 prototype were produced. The production was divided between the Ikarus A.D. and Rogozharski A-.D. factories, as Rogozharski was busy with the Zmaj A.D. factory with the licensed production of 100 Hawker Hurricane Mk.I fighters.


Fighting deployment
The 12 IK-3s produced had different fates. One machine (v. no. 2156 with fuselage number 6) was lost before the outbreak of fighting when it crashed into the Danube River in a simulated dogfight on 6 September 1940. The captain pilot Anton Ercigoj lost consciousness in an overload - the so-called "blackout" - and was killed. One machine was returned to the Rogozharsky factory and was used as the basis for the conversion to Series II. The 4 remaining machines were grounded at the beginning of the fighting (the so-called "April War") for periodic technical inspection. The other 6 machines capable of operational deployment were assigned to the 51st Fighter Group based at Zemun airfield, intended for the defence of Belgrade. Here they operated in squadrons 161 and 162, 3 in each.
On the morning of 6 April 1941, five IK-3s took off against a German air raid. After the end of the fighting, the pilots reported 5 victories, but suffered one loss - potporućnik Dušan Borćić was killed and 2 pilots were wounded (tehnički činovnik Eduard Bamfić, kapetan Savo Poljanec). The squadrons were left with only 3 airworthy machines. On the same day, IK-3 pilots made one more combat sortie and shot down 2 Ju 87s and one BF 109E. The following day, 7 April, 3 IK-3s flew again and the pilots reported several victories. NarednikMilislav Semiz landed with a badly damaged machine, but was able to replace it with a brand new one just delivered. On 11 April, this pilot again reported shooting down one Bf 109D, while kapetanTodor Gojić and narednikDusan Vujćić reported one Ju 87 each. This day was also the last day of fighting. The surviving 3 machines were burned by the airmen on the night of 11-12 April at the auxiliary airfield Veliki Radinci. Along with them, 5 Hawker Hurricanes, 8 (some sources say 11) Me 109s, 1 Me 110 and 1 Ikarus IK-2 and a certain number of school machines were burned. Pilots of the 51st Fighter Group claimed a total of 11 victories. The pilot narednik Milislav Semiz became the ace on the IK-3 with 4 kills. One of the pilots who flew the IK-3 was captain Savo Poljanec. This pilot was one of the 2 Yugoslavs who fought in the Combined Squadron from Tri oak airfield during the SNP period.

The end of the other remaining machines is unclear, according to existing photographs at least 2 IK-3s fell into German hands and at least one of them was tested at the Rechlin test centre.

The successful IK-3 design saw a revival attempt after the war, but with the Soviet VK 105PF2 engine from the Yak-3.

Na doplnění několik fotografií podle http://www.airwar.ru/enc/fww2/ik3.html

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In serial machines ochre motorboat Avia HS 12Ycrs (632 kW / 860 HP) put cannons Oerlikon MG FF with bubnom pre 60 nábojov. Len one machine Slovak series got rádiostanicu Telefunken FuG VII.
Neskôr got company Rogožarski an order for 48 machines, but the German attack on the Juhosláviu bolo in the building of flax 25 machines. One machine sa they prerábal on the engine DB-601 AND and it was considered sa aj about prestavbe on the engine Rolls-Royce Merlin II.


Hmotnosť empty lietadla - 2068 kg
Takeoff hmotnosť - 2630 kg
Max. the rate of pri the country - 421 km/h
Range 785 km
Availab 9400 m


Source:
Nemecek, Václav: Rogožarski IK-3, the Aviation and aerospace 1989 / 19.

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