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55-481: IK-3 can mean: Rogožarski IK-3 , a 1930s Yugoslav monoplane single-seat fighter FKU IK-3, Kharp , a penal colony in the Yamalo-Nenets Autonomous Okrug of Russia Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with the title IK-3 . If an internal link led you here, you may wish to change

110-476: A glider , specifically the Weltensegler , which performed its maiden flight in 1921. Its wings, which were externally braced, featured swept-back wingtips with negative incidence relative to the remainder of the main-plane. The Weltensegler also used a unique control system, consisting of a various pulleys and springs connected to a single control stick for the pilot, which warped the wing-tips as directed by

165-537: A Swiss-made Oerlikon FF 20 mm cannon . The replacement engine was less powerful, generating 860 hp (640 kW) at 4,000 m (13,000 ft). German-made Telefunken radios were to be installed but delays meant that only the first aircraft was delivered with a radio. The production aircraft were numbered 2–13; the prototype was number 1. The aircraft were built at the Rogožarski factory in Belgrade and assembled at

220-505: A general reluctance to adopt new concepts delayed the IK-3, and a contract for the production of the prototype was not signed until March 1937. The company selected for construction was Rogožarski A.D. in Belgrade. The first flight of the prototype was carried out by the VVKJ Test Group towards the end of May 1938 and the aircraft was then flown by a group of VVKJ officers who were to determine

275-471: A laterally stabilising dihedral , an uncommon feature for gliders of the era, which spanned roughly 40 percent of the inner wing span. Lippisch had chosen to adopt this configuration for its increased wingtip clearance, as well as the ill-founded belief that it would improve its stability during turns; however, studies have shown that normal gull wing configurations result in significantly less severe and more easily recoverable stalls. Inverted gull wings exhibit

330-556: A low-wing monoplane with retractable landing gear . Contemporary thinking within the VVKJ led them to evolve their initial ideas into a strut-braced gull-wing monoplane armed with a hub -firing autocannon and fuselage -mounted synchronised machine guns . The design concept for what became the Ikarus IK-2 was submitted to the VVKJ on 22 September 1933. With this work completed, Ilić and Sivčev had time to start preliminary development of

385-569: A new low-wing monoplane that could better meet and defeat the high-performance bomber prototypes then in development by potential adversaries. Ilić and Sivčev's new streamlined low-wing monoplane design had a retractable undercarriage. Like the IK-2 it was initially developed privately by the two men. A scale model was tested in the Eiffel-built wind tunnel in Paris, but the pair soon realised that they needed

440-500: A one-seater prototype in early July 1939, with its first flight scheduled for late 1941. At the time of the invasion, the production of the IK-5 prototype was well advanced, but it was not pursued either during or after the war. The advanced Yugoslav Ikarus S-49 fighter, produced after World War II, was based on the IK-3. When they entered service, the IK-3 suffered from minor equipment and instrument faults, largely caused by deficiencies in

495-668: A smaller wing area than the Hawker Hurricane and the Supermarine Spitfire , to achieve a higher speed for the engine power. In comparison to the Messerschmitt Bf 109 , the Yugoslav design had a shorter fuselage and smaller turning radius. It differed from British and German design concepts in that its proposed armament was concentrated in the fuselage. The designs were delivered to the VVKJ in time for approval by mid-1936, but

550-429: A successor to the Ikarus IK-2 fighter. Its armament consisted of a hub -firing 20 mm (0.79 in) autocannon and two fuselage -mounted synchronised machine guns . It was considered comparable to foreign aircraft such as the Messerschmitt Bf 109 E and came into service in 1940. The prototype crashed during testing; twelve production aircraft had been delivered by July 1940. Six IK-3s were serviceable when

605-592: A third engineer to help evaluate the design and determine the structural details. Slobodan Zrnić, the head of construction at the Yugoslav State Aircraft Factory in Kraljevo , was recruited, as he had worked as a specialist aircraft engineer in France. The project name for the IK-2 was changed from IK, standing for (Ljubomir) Ilić and Kosta (Sivčev), to IKZ, to include Zrnić. This name was changed, possibly due to

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660-536: A tight formation of three bombers; his aircraft received 56 hits from return fire, 20 of which were in the engine and propeller, but he managed to land the aircraft. The return of another IK-3 from the workshops meant that the number of serviceable IK-3s remained at three. It became difficult to continue activity from the 51st Fighter Group airfield at Zemun due to air attacks, so on 8 April the remaining IK-3s and Bf 109Es flew to an auxiliary airfield at Veliki Radinci , 50 km (31 mi) north-west of Belgrade, where

715-415: A trend of the glider industry during the 1930s, the gull wing remained a staple feature amongst high-performance sailplanes through to the 1950s. The gull wing design found its way into seaplanes by the early 1930s. As engine power increased, so did the need for large propellers that could effectively convert power to thrust. The gull wing allowed designers to ensure adequate propeller tip clearance over

770-511: The Axis invasion of Yugoslavia began on 6 April 1941. All six were in service with the 51st Independent Fighter Group at Zemun near Belgrade . Pilots flying the IK-3 claimed 11 Axis aircraft had been shot down during the 11-day war. According to one account, to prevent them from falling into German hands, the surviving aircraft and incomplete airframes were destroyed by their crews and factory staff. Another account suggests that one aircraft survived

825-533: The PZL P.11 and Soviet Polikarpov I-15 . The PZL P.11 was a further improvement of the PZL P.7 that was in production throughout the early 1930s. It possessed various cutting-edge features for the era in addition to the high-mounted gull wing, such as its all-metal structure and its metal exterior; according to aviation author Jerzy Cynk, the P.11 was commonly considered to have been the most advanced fighter aircraft of its kind in

880-658: The air force of the Axis puppet state, the Independent State of Croatia . The Germans had used a fence to separate the serviceable aircraft from other aircraft that had been earmarked for scrapping. In late June, while the German guards were distracted listening to news of the invasion of the Soviet Union , local communists, including former VVKJ mechanics, moved the fence. As a result, all the serviceable aircraft were scrapped, including

935-399: The "Polish Wing". The PZL P.1 led to a production model, the PZL P.7 , of which 149 were produced between 1932 and 1933. The gull wing was used to improve visibility in a high wing arrangement, because such wing could be thinnest by the fuselage, and in theory should limit pilot's view no more than A-pillars of a windscreen in a car body. It was used on multiple fighter aircraft, including

990-465: The 162nd Fighter Squadron ( Kapetan Todor Gogić). The IK-3 was then tested against Yugoslav Messerschmitt Bf 109Es in mock dogfights. The evaluation concluded that the IK-3 had several advantages over the Bf 109E; in particular, the Yugoslav aircraft was more manoeuvrable in level flight, enabling it to quickly get behind a pursuing Bf 109E by making tight horizontal turns. In its first year of service, an IK-3

1045-485: The 1930s, a derivative of the standard design, known as the inverted gull wing , was developed. It was chiefly used on single engine military aircraft with increasingly powerful engines. Before contra-rotating propellers came into use, such powers required larger diameter propellers but clearance between the propeller tip and ground had to be maintained. Long landing gear legs are heavy, bulky, and weaker than their shorter counterparts. The Vought F4U Corsair , designed from

1100-490: The 51st Fighter Group was placed under the 6th Fighter Regiment , which was responsible for the defence of Belgrade. The 51st Fighter Group was further reinforced the day before the invasion began, with the 102nd Fighter Squadron equipped with Bf 109Es. When the invasion began on 6 April, the two IK-3 squadrons had only three serviceable aircraft each. The invasion commenced with a wave of 234 German dive bombers and medium bombers attacking Belgrade. Escorted by 120 fighters,

1155-424: The IK-3 encouraged the three designers to pursue the idea of a twin-engined fighter, capable of long-range reconnaissance, photographic reconnaissance and operation as a "destroyer" or heavy fighter similar to the Messerschmitt Bf 110 . The concept included both one-seater and two-seater versions. Development of this new aircraft, designated IK-5, was commenced on the back of the success of the IK-3. The VVKJ ordered

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1210-448: The Ju 87. These wings, which comprised conventional Junkers double-wing construction, reportedly gave the Ju 87 a considerable advantage over its contemporaries during take-off; relatively large lift forces were created through the aerofoil even when flown at a shallow angle, reducing take-off and landing runs. They also provided a high level of ground visibility to the pilot, as well as enabling

1265-459: The Polish aircraft designer Zygmunt Puławski developed the PZL P.1 , an experimental fighter aircraft ; a major innovation of the PZL P.1 was its relatively high-mounted gull wing. Seeking to protect his new wing arrangement, Puławski filed for an associated patent for this wing arrangement during the following year. The arrangement devised by Puławski has been referred to as the "Puławski Wing" or

1320-434: The Polish aviation designer Zygmunt Puławski developed a range of fighter aircraft during the late 1920s and early 1930s; in particular, the PZL P.11 , which possessed various cutting-edge features for the era in addition to its high-mounted gull wing, has been described as being the most advanced fighter aircraft of its kind in the world upon its introduction. The PZL P.11 served as Poland's primary fighter aircraft during

1375-654: The VVKJ or in the aeronautical industry. Ljubomir Ilić and Kosta Sivčev went through this program but, when they returned to Yugoslavia, both were employed in administrative work. Frustrated by this, they decided in 1931 to design a replacement for the Czechoslovakian -built Avia BH-33 E biplane fighter in service with the VVKJ. Working in a basement in Belgrade, and later in Ilić's apartment in Novi Sad , they secretly devoted their spare time to work on their design. They originally planned

1430-403: The Yugoslav aeronautical industry which had resulted in a mixture of foreign and Yugoslav-made instruments being fitted to the aircraft. The Yugoslav Minister of War approved the acquisition of a further 48 IK-3s to be delivered in 1941–1942. The operational aircraft were allocated to the 51st Independent Fighter Group at Zemun, six each to the 161st Fighter Squadron ( Kapetan Savo Poljanec) and

1485-413: The best employment for it within the VVKJ, along with tactics to be used in Yugoslav conditions. These pilots observed that the controls were highly sensitive; the only real criticisms related to the visual distortion caused by the curved panels of the canopy . Some pilots believed that the fuselage-mounted armament should be supplemented by two wing-mounted machine guns. The test pilots also had to compare

1540-495: The bombers reached Belgrade at 07:00; they were met by the 51st Fighter Group, minus an IK-3 from the 161st Fighter Squadron that had developed engine trouble after takeoff and was unable to engage. The other five IK-3s were the first to meet the initial bomber wave but they were almost immediately attacked by Bf 109Es of Jagdgeschwader 77 . The pilots of the IK-3s claimed five German aircraft, and one aircraft from each Yugoslav squadron

1595-602: The canopy to provide better visibility. The instrument layout was improved and the upper rear fuselage behind the pilot's seat was re-shaped. The folding undercarriage leg covers were replaced by single plates. The main changes were the replacement of the engine with a modified version of the Hispano-Suiza 12Y engine made under licence by the Czechoslovak company Avia and the replacement of the Hispano-Suiza HS.404 cannon by

1650-447: The company hangar at Zemun. The first six aircraft were delivered by late March 1940; delivery of the rest of the order was delayed until July due to delays by foreign suppliers. The first production aircraft was delivered to the VVKJ Test Group, where it was confirmed that the production aircraft were free of the faults in the prototype. The Test Group determined that the maximum speed, previously estimated at 540 km/h (340 mph),

1705-472: The first aircraft to feature the gull wing, starting with the Weltensegler in 1921; it was not until the record-breaking Fafnir at the end of that decade did the configuration gain popularity. Beyond becoming popular for the next three decades amongst high-performance gliders, various ground-based aircraft and flying boats also adopted various forms of gull wings. It rose to particular prominence in Poland, where

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1760-535: The following day all remaining aircraft of the 6th Fighter Regiment, including the remaining IK-3s, were burned by their crews. According to aviation writers Dragan Savić and Boris Ciglić, one serviceable IK-3 was captured by the Germans in April 1941 and it was joined by another by the end of June. Both aircraft were located at Zemun, along with 23 other former VVKJ aircraft in working condition that were destined for service with

1815-610: The invasion and was later destroyed by sabotage . The IK-3 design was the basis for the post-war Yugoslav-built Ikarus S-49 fighter. In the late 1920s, the Royal Yugoslav Air Force ( Serbian : Vazduhoplovstvo vojske Kraljevine Jugoslavije , VVKJ) and the Royal Aero Club of Yugoslavia helped send aspiring aeronautical engineers to France to gain knowledge. It was intended that after this advanced training, they would return to Yugoslavia and be offered specialist roles in

1870-508: The link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=IK-3&oldid=1191870068 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages Rogo%C5%BEarski IK-3 The Rogožarski IK-3 was a 1930s Yugoslav monoplane single-seat fighter , designed by Ljubomir Ilić, Kosta Sivčev and Slobodan Zrnić as

1925-417: The main factor had been the pilot's handling of the highly sensitive controls. The loss of the prototype and some changes in the construction of the production model delayed the fulfilment of the contract. Further tests were conducted on the wing and it was found to withstand a g-force of 14. Modifications were made for the production model, including the use of flat plexiglass panels in the windscreen and

1980-462: The mid to late 1930s, while its further development, the PZL P.24 , served in the air forces of several countries and was a major success of the Polish aircraft industry. Various flying boats , such as the Short Knuckleduster , Dornier Do 26 , and PBM Mariner , also adopted the gull wing configuration, primarily as it enabled the engines to be positioned higher above the water. A variant of

2035-432: The onset as a carrier-based fighter, not only had the largest propeller of any U.S. fighter, but was also expected to face rough landings aboard a pitching carrier deck. By adopting the inverted gull wing, the landing gear could be shorter and allowed to retract straight back (while twisting through 90º to place the mainwheels atop the lower gear strut ends) , the latter factor improving internal wing space. The anhedral of

2090-606: The opposite stall behaviour, but both normal and inverted gull wings impede lift-to-drag ratio and climb performance. The performance demonstrated by Fafnir, such as a 220 km (140 mi) flight between the Wasserkuppe and Magdeburg in late August 1930 that established a new world record, quickly encouraged numerous aircraft designers to perform their own investigations into the gull wing. Accordingly, numerous other gliders, as well as other platforms, would soon feature broadly similar wing configurations as well. Having become

2145-513: The performance of the IK-3 with the Hawker Fury (a biplane), Heinkel He 112 , Morane-Saulnier M.S. 405 and Hawker Hurricane. They concluded that the IK-3 most closely matched the Morane-Saulnier; the Yugoslav aircraft was 40 km/h (25 mph) faster. In November 1938, the VVKJ placed an order with Rogožarski for 12 aircraft. On 19 January 1939, test pilot Kapetan Milan Pokorni put

2200-455: The pilot. This unorthodox method relied upon the incidence changing with the increase and release of tension, and was also expected to confer increased stability in pitch and roll by automatic changes in wing-tip incidence; however, it gave no direct control over the wing-tips. The flying career of the Weltensegler was very brief, it being destroyed during the 1921 Rhön gliding competition after

2255-432: The prototype into a steep dive. When he reached 400 m (1,300 ft), the windscreen detached from the aircraft; Pokorni pulled up hard and the strain broke off half of the starboard wing. The aircraft crashed, and Pokorni was killed. An inquiry determined that modifications to the windscreen had contributed to the accident. Engineers recalculated the stress factors on the airframe and they were found to be safe, and

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2310-459: The remaining IK-3s were scrambled with the rest of the 51st Fighter Group but the IK-3 pilots claimed no victories. A joint claim was made during the third German attack at 14:00, a twin-engined bomber by Gogić and another pilot from the 162nd Fighter Squadron. The following day, the IK-3 pilots made five or six sorties against German bomber formations and their fighter escorts, and claimed three bombers between them. At 17:00, Milislav Semiz attacked

2365-535: The similarities between the Cyrillic " З " (Z) and the Arabic numeral "3", and the aircraft became known as the IK-3. The aircraft was to be powered by a Hispano-Suiza 12Y 29 engine, generating 980 hp (730 kW) at an altitude of 5,000 m (16,000 ft). The designers favoured manoeuvrability over speed, trying to find a compromise between the German and British concepts of a modern monoplane fighter. The design had

2420-527: The standard configuration, the inverted gull wing , has been used on numerous fighters to facilitate the use of shorter landing gear and to provide sufficient ground clearance for their propellers. The most distinctive feature of the Junkers Ju 87 Stuka , a German ground attack aircraft used during the Second World War , is probably its inverted gull wing configuration. The gull wing was first implemented on

2475-408: The surviving aircraft of the 6th Fighter Regiment were concentrated. Poor weather made operations impossible until 11 April, when Semiz shot down a Bf 110 that had strafed the airfield. Later that day, Gogić and another IK-3 pilot claimed one Junkers Ju 87 'Stuka' dive bomber each during a patrol. That night, German troops approached within 15 km (9.3 mi) of the airfield at Veliki Radinci and

2530-421: The time of the Axis invasion, and the only prototype to be fitted with a non-production engine was deliberately destroyed by factory personnel during the invasion, along with the incomplete production aircraft. Development of a dual-control two-seat trainer variant of the IK-3 had commenced but pressure on the design team had delayed the completion of the project when the invasion intervened. The development of

2585-612: The two IK-3s. "The IK-3s put up a valiant resistance against the Luftwaffe," wrote William Green , "scoring a number of 'kills' before they were finally destroyed in combat." Aviation writers Šime Oštrić and Čedomir Janić credit the IK-3 pilots with 11 victories, Semiz being the most successful, with four victories. Data from Oštrić & Janić General characteristics Performance Armament Related development Aircraft of comparable role, configuration, and era Related lists Gull wing Gliders were

2640-407: The water by placing the engines on the highest point of the wing. The alternative was placing the engine on a pylon. The first flying boat to utilize the gull wing configuration may have been the Short Knuckleduster , which first flew in 1933. The Dornier Do 26 , a high-speed airliner and transport platform, of which six aircraft were built, made its first flight during 1938. The configuration

2695-469: The wing failed during a sharp spiralling dive at excessive speed, resulting in the death of Willy Leusch, the Weltensegler's company test pilot. Following the Weltensegler's tragic loss, the gull wing was avoided by the majority of aircraft designers for almost a whole decade. During 1930, Alexander Lippisch 's record-breaking Fafnir represented a high-profile comeback for the gull wing, which contributed to its resurgence shortly thereafter. Fafnir featured

2750-422: The wing's center-section also permitted the wing and fuselage to meet at the optimum angle for minimizing drag , without using wing root fairings or other measures. Another reason for having an inverted gull wing is to permit clearance for a large external bomb load, as on the Junkers Ju 87 Stuka . The inverted gull wing has been described by aviation author Manfred Griehl as being the most distinctive feature of

2805-474: The world upon its introduction. The P.11 served as Poland's primary fighter aircraft during the mid to late 1930s, participating in the Polish campaign of 1939 to resist an invasion by neighbouring Nazi Germany . As a consequence of the rapid aeronautical advances made during the late 1930s, the P.11 was outclassed by newer fighters such as the Messerschmitt Bf 109 at the onset of the conflict. Examples: During

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2860-542: Was 527 km/h (327 mph), at an altitude of 5,400 m (17,700 ft). By July 1940, a further series of 25 IK-3s had commenced construction at the Rogožarski factory. A shortage of engines was a major obstacle to mass production and development of the IK-3, so tests were conducted with more powerful engines, including the Daimler-Benz DB 601 , Rolls-Royce Merlin II and Hispano-Suiza 12Y51. The tests were incomplete at

2915-552: Was also used on the US Navy 's PBM Mariner and P5M Marlin maritime patrol aircraft . The emergence of long range, land-based jets in the 1950s and the subsequent demise of the seaplane prevented widespread use of the gull wing, although it was still used in some post-war designs, like Beriev Be-12 Chaika (the name means 'gull' in Russian). Examples: During the late 1920s, the gull wing design found its way into landplanes. In 1928,

2970-517: Was lost when one of the squadron commanders, Kapetan Anton Ercigoj, was making a mock attack on a Potez 25 over the confluence of the Sava and Danube rivers. After passing below the Potez, he went into a climb with the intention of performing a loop. His rate of climb was too steep and the aircraft fell into a spin at low altitude and hit the water. Before the Axis invasion of Yugoslavia in early April 1941,

3025-436: Was lost. Poljanec had claimed a twin-engined bomber and a Bf 109E; when he returned to Zemun in his badly damaged aircraft, he was strafed by a Messerschmitt Bf 110, which further damaged his aircraft and wounded him. After this encounter, only three IK-3s were serviceable, including the one that had developed engine difficulties prior to the first German wave. A second wave of German aircraft arrived over Belgrade at 10:00 and

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