51-537: The Ikarus IK-2 was a 1930s high-wing, single-seat, monoplane fighter aircraft of Yugoslav design built for the Royal Yugoslav Army Air Force . The IK-2 was designed by French-trained engineers Kosta Sivčev and Ljubomir Ilić, who saw the desirability of developing a home-grown aircraft industry. A gull-wing design, it was armed with a hub -firing autocannon and fuselage -mounted synchronised machine guns . Just 12 production models were built, as
102-525: A biplane with a 600 shp (450 kW) engine was the ultimate in fighter design. Despite this opposition, support from Stanojević and some younger pilots meant that the concept was approved, and in 1934 a prototype was ordered from the Ikarus A.D. factory in Zemun near Belgrade, for delivery by the end of that year. The prototype was designated IK-1, with the "IK" standing for (Ljubomir) Ilić and Kosta (Sivčev). It
153-608: A light aircraft, the configuration is significant because it offers superior visibility to the pilot. On light aircraft, shoulder-wings tend to be mounted further aft than a high wing, and so may need to be swept forward to maintain correct center of gravity . Examples of light aircraft with shoulder wings include the ARV Super2 , the Bölkow Junior , Saab Safari and the Barber Snark . A high wing has its upper surface on or above
204-455: A patrol in poor flying weather. One of the IK-2s managed to overshoot and climbed to meet them, but the other was unable to, and had to complete its landing. Podnarednik (Junior Sergeant) Branko Jovanović used the extreme manoeuvrability of his IK-2 to avoid the nine Bf 109s that swooped in to attack, while a total of eight Hurricanes and five more IK-2s from the 4th Fighter Regiment scrambled to meet
255-407: A pendulous fuselage which requires no wing dihedral for stability; and, by comparison with a low-wing, a shoulder-wing's limited ground effect reduces float on landing. Compared to a low-wing, shoulder-wing and high-wing configurations give increased propeller clearance on multi-engined aircraft. On a large aircraft, there is little practical difference between a shoulder wing and a high wing; but on
306-464: A popular configuration for amphibians and small homebuilt and ultralight aircraft . Although the first successful aircraft were biplanes, the first attempts at heavier-than-air flying machines were monoplanes, and many pioneers continued to develop monoplane designs. For example, the first aeroplane to be put into production was the 1907 Santos-Dumont Demoiselle , while the Blériot XI flew across
357-659: A replacement for the Czechoslovakian -built Avia BH-33 E biplane fighter then in service with the VVKJ. Working in a basement in Belgrade , then in Ilić's apartment in Novi Sad , they devoted their spare time to secretly working on their design. Their original concept was for a low-wing monoplane with a retractable undercarriage, but contemporary thinking led them to modify their initial design into
408-653: A scheme promoted by the Royal Yugoslav Army Air Force ( Serbo-Croatian : Vazduhoplovstvo vojske Kraljevine Jugoslavije , VVKJ) and the Royal Aero Club of Yugoslavia sent aspiring aeronautical engineers to France to develop their knowledge. It was intended that after this advanced training, they would return to Yugoslavia and be offered specialist roles in 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, in 1931 they decided to design
459-413: A strut-braced high-wing monoplane armed with a hub -firing autocannon and fuselage -mounted synchronised machine guns . The gull-wing design emphasised power and manoeuvrability over other characteristics. The aircraft was designed around a French-made 12-cylinder Hispano-Suiza 12Ycrs engine with a Hispano-Suiza HS.404 20 mm (0.79 in) autocannon mounted between the cylinder banks of
510-461: A third test flight the next day, which involved more unplanned aerobatics. When the aircraft was at 1,000 m (3,300 ft), Bajdak put it into a shallow dive and pulled up abruptly at high speed, at which point the wing fabric began to tear rapidly, to the extent that it could be seen from the ground. The aircraft dropped into a spin to starboard , and Bajdak baled out safely while the IK-1 crashed into
561-489: A wing of a given size, the weight reduction allows it to fly slower and with a lower-powered and more economical engine. For this reason, all monoplane wings in the pioneer era were braced and most were up until the early 1930s. However, the exposed struts or wires create additional drag, lowering aerodynamic efficiency and reducing the maximum speed. High-speed and long-range designs tend to be pure cantilevers, while low-speed short-range types are often given bracing. Besides
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#1732863353823612-432: Is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes , which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing configuration and is the simplest to build. However, during the early years of flight, these advantages were offset by its greater weight and lower manoeuvrability, making it relatively rare until
663-483: Is believed that the prototype was complete by September 1934, but the first flight was delayed due to concerns about the wing structure. The following month, Bajdak was appointed as test pilot for the prototype, but he did not co-operate in the preparations for the maiden flight, and decided to develop his own test program. Permission was granted for flight testing to begin in April 1935, and Bajdak conducted his first flight in
714-410: Is that the fuselage is closer to the ground which eases cargo loading, especially for aircraft with a rear-fuselage cargo door. Military cargo aircraft are predominantly high-wing designs with a rear cargo door. A parasol wing is not directly attached to the fuselage but held above it, supported by either cabane struts or a pylon. Additional bracing may be provided by struts or wires extending from
765-564: The English Channel in 1909. Throughout 1909–1910, Hubert Latham set multiple altitude records in his Antoinette IV monoplane, eventually reaching 1,384 m (4,541 ft). The equivalent German language term is Eindecker , as in the mid-wing Fokker Eindecker fighter of 1915 which for a time dominated the skies in what became known as the " Fokker scourge ". The German military Idflieg aircraft designation system prior to 1918 prefixed monoplane type designations with an E , until
816-665: The Fokker D.VIII and Morane-Saulnier AI in the later part of the First World War. A parasol wing also provides a high mounting point for engines and during the interwar period was popular on flying boats, which need to lift the propellers clear of spray. Examples include the Martin M-130 , Dornier Do 18 and the Consolidated PBY Catalina . Compared to a biplane , a parasol wing has less bracing and lower drag. It remains
867-508: The German -led Axis invasion of Yugoslavia commenced on 6 April 1941, only eight IK-2s were serviceable. One had been damaged in a landing accident, two were at the workshops in Zagreb being repaired, and the fourth unserviceable machine was in a badly damaged condition at Bosanski Aleksandrovac. That day and the next, the 107th Fighter Squadron patrolled over Bosnia but did not make any contact with
918-451: The braced parasol wing became popular on fighter aircraft, although few arrived in time to see combat. It remained popular throughout the 1920s. On flying boats with a shallow hull, a parasol wing allows the engines to be mounted above the spray from the water when taking off and landing. This arrangement was popular on flying boats during the 1930s; a late example being the Consolidated PBY Catalina . It died out when taller hulls became
969-443: The fixed conventional landing gear was spatted and mounted off the wing struts. The fixed tailwheel was also spatted. The enclosed cockpit was located behind the wing. The horizontal stabilizer on each side was braced from below with two rigid braces from the lower tailcone, and tied from above with two flying wires from the vertical stabilizer . The three-bladed propeller was manually adjustable in pitch. Considerable work
1020-695: The 1930s, the cantilever monoplane was fast becoming the standard configuration for a fixed-wing aircraft. Advanced monoplane fighter-aircraft designs were mass-produced for military services around the world in both the Soviet Union and the United States in the early–mid 1930s, with the Polikarpov I-16 and the Boeing P-26 Peashooter respectively. Most military aircraft of WWII were monoplanes, as have been virtually all aircraft since, except for
1071-457: The 1930s. Since then, the monoplane has been the most common form for a fixed-wing aircraft. The inherent efficiency of the monoplane is best achieved in the cantilever wing, which carries all structural forces internally. However, to fly at practical speeds the wing must be made thin, which requires a heavy structure to make it strong and stiff enough. External bracing can be used to improve structural efficiency, reducing weight and cost. For
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#17328633538231122-536: The Germans. For the following seven or eight minutes, a furious dogfight ensued over Novo Topola, during which two German aircraft were claimed and two Hurricanes and one IK-2 were lost. German records indicate that only one of their aircraft was lost, and that the pilot survived. Podnarednik Stikić survived the loss of his IK-2, but was badly wounded. The Germans, low on fuel, broke off and headed north. The following day, one IK-2 force landed due to engine failure, reducing
1173-579: The IK-2 displayed overall superiority over the British-built aircraft. At one point, Bajdak declared his continuing doubts about the aircraft, and Dobnikar challenged him to a duel, with Bajdak flying his preferred aircraft, the Fury I. After Dobnikar won the climbing competition and a race to Zemun and back from Belgrade, the final dogfight forced Bajdak to concede that the IK-2 was the better aircraft. On 20 November 1937,
1224-501: The IK-2s were transferred to the 4th Fighter Regiment in Zagreb until licence-built Hawker Hurricanes were delivered from Zemun, after which the IK-2s were to be transferred to the 5th Fighter Regiment in Niš . By the end of 1940, all the production IK-2s were concentrated in the 107th Fighter Squadron of the 34th Fighter Group, which consisted solely of IK-2s. This was only an interim allocation, as
1275-410: The VVKJ submitted a proposal to order a batch of 12 IK-2s, which was approved the following month. The production version included some additional improvements, but continued testing resulted in further delays, with the aircraft not entering service for another year. By this time, international consensus had coalesced around the superiority of the low-wing monoplane, and the IK-2 was already obsolescent by
1326-476: The aircraft more manoeuvrable, as on the Spitfire ; but aircraft that value stability over manoeuvrability may then need some dihedral . A feature of the low-wing position is its significant ground effect , giving the plane a tendency to float farther before landing. Conversely, this ground effect permits shorter takeoffs. A mid wing is mounted midway up the fuselage. The carry-through spar structure can reduce
1377-514: The aircraft was obsolescent at the time it was brought into service in 1935, and only eight were serviceable at the time of the German -led Axis invasion of Yugoslavia in April 1941. After the defeat of Yugoslavia, the remaining four aircraft were taken onto the strength of the air force of the Axis puppet state , the Independent State of Croatia , but none survived the war. In the late 1920s,
1428-457: The aircraft was well-designed, but it needed more testing. At this point, Ikarus decided to build a second prototype, as it was evident that the hand-sewn fabric seam on the wing had not stood up to the strain of aerobatics, and their workmanship was in question. The second prototype took 10 months to build, with the two designers closely involved. The main difference from the IK-1 was that the IK-2 had wings covered with metal sheeting, leaving only
1479-521: The approval of the Fokker D.VIII fighter from its former "E.V" designation. However, the success of the Fokker was short-lived, and World War I was dominated by biplanes. Towards the end of the war, the parasol monoplane became popular and successful designs were produced into the 1920s. Nonetheless, relatively few monoplane types were built between 1914 and the late 1920s, compared with the number of biplanes. The reasons for this were primarily practical. With
1530-513: The beginning of 1942, there were four IK-2s in service with the ZNDH, but they lacked spare parts. Later that year, an operational IK-2 was observed at Rajlovac airfield near Sarajevo, and in October 1943, two of the IK-2s were operating from Zalužani airfield north of Banja Luka, and remained there for nearly a year conducting strafing missions. At the end of 1943, all four IK-2s were still in service, but at
1581-531: The commander of the 2nd Mixed Air Brigade ordered the remaining aircraft of the 4th Fighter Regiment to be destroyed, and all personnel to withdraw via road to Sarajevo . At the end of the brief campaign, the Air Force of the Independent State of Croatia ( Croatian : Zrakoplovstvo Nezavisne Države Hrvatske , ZNDH) made the three or four surviving IK-2s serviceable using other captured aircraft for spares. At
Ikarus IK-2 - Misplaced Pages Continue
1632-497: The end of the following year, just two IK-2s remained. No IK-2s survived the war. A proposed development of the IK-2 was the IK-4, a dual control two-seater fast reconnaissance monoplane, but it was never ordered. Source : Oštrić & Janić (1973 , pp. 191–192) General characteristics Performance Armament Aircraft of comparable role, configuration, and era Related lists Monoplane A monoplane
1683-641: The enemy. Two machines conducted a combat air patrol over the airfield of the 8th Bomber Regiment at Nova Topola . This pattern continued the following day without incident, but patrol duration and coverage was limited by the short range of the aircraft. On 8 April, a patrol unsuccessfully gave chase to a lone German reconnaissance aircraft, and later in the day, one of the IK-2s force landed, leaving seven operational aircraft. About 14:00 on 9 April, two Staffeln of German Messerschmitt Bf 109 fighters from II. Gruppe of Jagdgeschwader 54 were observed heading towards Nova Topola just as two IK-2s were landing after
1734-402: The engine and firing through the propeller hub. This powerful 860 shaft horsepower (640 kW ) engine combined with the hub-firing cannon mandated the use of a metal fuselage. Other armament consisted of two synchronised French-made 7.9 mm (0.31 in) Darne machine guns , mounted under and to each side of the engine. The wing was braced with two struts on each side of the fuselage;
1785-402: The fuselage sides. The first parasol monoplanes were adaptations of shoulder wing monoplanes, since raising a shoulder mounted wing above the fuselage greatly improved visibility downwards, which was useful for reconnaissance roles, as with the widely used Morane-Saulnier L . The parasol wing allows for an efficient design with good pilot visibility, and was adopted for some fighters such as
1836-433: The general variations in wing configuration such as tail position and use of bracing, the main distinction between types of monoplane is where the wing is mounted vertically on the fuselage . A low wing is one which is located on or near the bottom of the fuselage. Placing the wing low allows good visibility upwards and frees the central fuselage from the wing spar carry-through. By reducing pendulum stability, it makes
1887-411: The ground. Critics exploited the accident to undermine the IK-1 concept, with Bajdak joining those criticising the aircraft. The three flights were not considered sufficient to give a verdict on the design, and the debate over its future was fierce. This placed significant pressure on the designers, as every element of the aircraft design was subsequently attacked. Eventually, it was generally agreed that
1938-436: The head of the technical department of the VVKJ, Potpukovnik (Lieutenant Colonel) Srbobran Stanojević, with their design. Stanojević was surprised but impressed with their work and an official report proposing to build the design was presented on 22 September 1933. Some senior VVKJ officers opposed the concept, as did Kapetan (Captain) Leonid Bajdak, an "acknowledged outstanding exponent of fighter tactics", who considered that
1989-415: The low engine powers and airspeeds available, the wings of a monoplane needed to be large in order to create enough lift while a biplane could have two smaller wings and so be made smaller and lighter. Towards the end of the First World War, the inherent high drag of the biplane was beginning to restrict performance. Engines were not yet powerful enough to make the heavy cantilever-wing monoplane viable, and
2040-410: The norm during World War II, allowing a high wing to be attached directly to the hull. As ever-increasing engine powers made the weight of all-metal construction and the cantilever wing more practical — first pioneered together by the revolutionary German Junkers J 1 factory demonstrator in 1915–16 — they became common during the post–World War I period, the day of the braced wing passed, and by
2091-513: The number of serviceable IK-2s to five. Despite deteriorating weather conditions and revolts within the Yugoslav forces, combat patrols continued. At 12:00 on 11 April, all aircraft were grounded by the weather. On 12 April, aircraft of the 4th Fighter Regiment took to the air again, chasing German reconnaissance aircraft, but the IK-2s did not record any victories. The following day, the 4th Fighter Regiment continued carrying out sorties, but around 12:00
Ikarus IK-2 - Misplaced Pages Continue
2142-418: The other squadron of the group was equipped with Hurricanes, and as soon as the 107th Fighter Squadron could be equipped with Hurricanes, the IK-2s were to move to the 5th Fighter Regiment. The threat of war overtook this planned deployment, and on 13 March 1941, the IK-2s of the 107th Fighter Squadron were moved to Bosanski Aleksandrovac near Banja Luka , under the command of Kapetan Zarko Vukajlović. When
2193-403: The prototype on 22 April 1935. For this initial uneventful flight, no weapons were installed and a light fuel load was used. The following day, Bajdak put the IK-1 into unplanned aerobatic manoeuvres, after which the wing fabric was observed as being slack. An official from Ikarus checked it and stated that this would resolve once the fabric varnish had completely dried. Bajdak took the aircraft for
2244-402: The rear fuselage and tailplane fabric covered. The new wing was tested with both fabric and metal covering at the request of the VVKJ. Other changes were a radiator of reduced size and improved shape, and modified air intakes, making for a more streamlined fuselage. The two Darne machine guns were replaced with two 7.92 mm (0.31 in) Browning/FN machine guns. After the second prototype
2295-459: The time it was delivered to VVKJ fighter units. The first six production aircraft were delivered to the 6th Fighter Regiment of the VVKJ, based at Zemun, in early 1939. The pilots subjected them to considerable additional testing, before they entered normal service around mid-year. The remaining six entered service during the remainder of 1939. The aircraft were delivered without radios or armament, which were fitted in VVKJ workshops. In October 1939,
2346-449: The top of the fuselage. It shares many advantages and disadvantages with the shoulder wing, but on a light aircraft, the high wing has poorer upwards visibility. On light aircraft such as the Cessna 152 , the wing is usually located above the cabin, so that the wing spar passes over the occupants' heads, leaving the wing in the ideal fore-aft position. An advantage of the high-wing configuration
2397-439: The useful fuselage volume near its centre of gravity, where space is often in most demand. A shoulder wing (a category between high-wing and mid-wing) is a configuration whereby the wing is mounted near the top of the fuselage but not on the very top. It is so called because it sits on the "shoulder" of the fuselage, rather than on the pilot's shoulder. Shoulder-wings and high-wings share some characteristics, namely: they support
2448-441: The various characteristics of the aircraft. After gaining complete mastery of the aircraft, he conducted some aerobatic manoeuvres during a visit by the future Turkish president İsmet İnönü , which included a complete inverted loop. In mid-October 1935, Dobnikar used the second prototype to break the unofficial European air speed record for an aircraft with a fixed undercarriage, attaining a speed of 435 km/h (270 mph), which
2499-470: Was also a Yugoslav air speed record. The aircraft was able to achieve greater than expected power at altitudes of 4,000–5,000 m (13,000–16,000 ft). Dobnikar completed the testing program and submitted his report to the VVKJ on 23 May 1937. After VVKJ acceptance, a group of pilots conducted 16 mock dogfights between the IK-2 and the Hawker Fury I biplane already in service with the VVKJ, during which
2550-433: Was delivered, the aircraft was placed in the hands of a different test pilot, Poručnik (1st Lieutenant) Janko Dobnikar, who conducted its first flight on 24 August 1934. Dobnikar had worked closely with the designers and Ikarus during its construction and static testing, and his suggestions had resulted in an improved cockpit layout. He strictly followed a completely new test program, while installed testing equipment recorded
2601-481: Was needed to fully develop the design but, by early 1933, the two men had moved the project through the pre-project, basic aerodynamic and evaluation stages, including the building of a wooden scale model that Ilić took to Paris to test in the Eiffel -built wind tunnel. Up to this point, the two men had received no outside help, and had been forced to borrow from family to keep the project going. They then decided to approach
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