Ikarus S-49

Ikarus S-49
Role	fighter-bomber
Manufacturer	Ikarus Aircraft factory
Designed by	Kosta Sivcev, Svetozar Popovic, Slobodan Zrnic
Introduced	1946
Retired	1961
Primary user	Yugoslav Air Force
Number built	158

The Ikarus S-49 was one of the first fighter aircraft produced in Yugoslavia after World War II by the Ikarus Aircraft factory. It was a conventional, low-wing cantilever monoplane with retractable tailwheel undercarriage and bore a strong resemblance to the Yakovlev Yak-9, although it was in fact a fresh design.

Development

After the Resolution of Informbiro in 1948 and breakup with Soviet Union, Yugoslavia was forced to rely on its domestic military industry. The same constructors that built the Rogozarski IK-3 before the war, engineers Kosta Sivcev, Slobodan Zrnic and Svetozar Popovic, used existing technical documentation of IK-3 to construct a new fighter aircraft, the Ikarus S-49. The first prototype of the S-49A flew in the June of 1949. The first operational aircraft were delivered to combat units at the beginning of 1950.
The S-49A was of mixed construction, with Soviet built VK-105 engines which were no longer available after 1948. Therefore, it was decided to produce a new version of aircraft powered by the similar French Hispano-Suiza 12Z-17 engine. Because of the bigger and heavier engine, the new aircraft had to be of all metal construction with a much longer nose. While the aircraft was mainly built by Ikarus, the wings and tail were built by the SOKO factory in Mostar ^[1]. The armament remained the same as with Ikarus S-49A and it consisted of one 20 mm MG-151 German cannon and two 12.7 mm Colt Browning machineguns. In addition, under wing racks for two 50 kg bombs or four 127 mm HVAR missiles were added.
At the beginning of 1952, the new fighter aircraft Ikarus S-49C was introduced in to the units of Yugoslav Air Force. About 130 S-49C were produced during the fifties and they remained in service until 1961 ^[1].

Variants

• S-49A - mixed construction and Klimov M-105 engine (45 built)
• S-49C - all-metal construction and Hispano-Suiza 12Z engine (113 built)

Operators

•  Yugoslavia
  • Yugoslav Air Force

Specifications (Ikarus S-49C)

Data from The Complete Book of Fighters ^[1]

General characteristics

• Crew: one pilot
• Length: 9.06 m (29 ft 8¾in)
• Wingspan: 10.30 m (33 ft 9½ in)
• Height: 2.90 m (9 ft 6 in)
• Wing area: 16.65 m² (179 ft²)
• Empty weight: 2,818 kg ^[2] (6,200 lb)
• Max takeoff weight: 3,568 kg^[2] (7,850 lb)
• Powerplant: 1× Hispano-Suiza 12Z-17 water cooled V-12, 1,104 kW (1,500 hp)

Performance

• Maximum speed: 628 km/h (339 knots, 390 mph) at 1,525 m (5,000 ft)
• Range: 690 km (373 nm, 429 mi)
• Service ceiling: 10,000 m (33,000 ft)
• Climb to 6,000 m (19,700 ft): 6 min 54 sec ^[3]

Armament

• 1 × 20 mm MG-151/20 cannon
• 2 × .50 Colt Browning M2 machine guns with 650 rounds per gun
• 2 × 50 kg (110 lb) bombs or 4 × 5 in HVAR missiles

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Ikarus IK 2

Ikarus IK 2
Role	Fighter
Manufacturer	Ikarus A.D.
Designed by	Kosta Sivcev, Ljubomir Ilic
First flight	22 April 1935
Introduced	1935
Retired	1944
Primary users	Royal Yugoslav Air Force Air Force of the Independent State of Croatia
Number built	12

The Ikarus IK-2 was a 1930s high-wing, all-metal, single seat, monoplane fighter aircraft of indigenous design built for the Yugoslav Air Force. The IK-2 was designed by Kosta Sivčev and Ljubomir Ilić, who saw the desirability of a home-developed aircraft industry in their country, whose aerial forces had up to that point been supplied by machines from abroad.

Contents 1 Design and development 2 Operational history 3 Further Development 4 Variants 5 Operators 6 Specifications (Ikarus IK-2)

Design and development

The prototype, designated the IK-L1, of the design was ordered from Ikarus A.D. in 1934, and was delivered for test in 1935. The aircraft was powered by a Hispano-Suiza 12Ycrs inline engine. The forward-firing armament consisted of a 20 mm HS-404 cannon mounted under the engine, and two 7.92 mm Darne machine guns, mounted under and to each side of the engine. The design was similar to the Polish PZL P.8, sharing its Pulawski wing (gull-wing) design, giving the pilot an excellent view.^[1] The wing on each side was braced with two struts; the fixed conventional landing gear was spatted and mounted off the wing struts. The fixed tailwheel was also spatted. The pilot was installed aft of the wing in an enclosed cockpit. 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.^[2]
Captain Leonid Bajdak, a biplane advocate, tested the IK-1 in flight. During a full range of tests on the third flight the aircraft failed to pull out of a power dive and crashed. Bajdak bailed out and survived but claimed the IK-1 was not suitable as a fighter. Investigation of the wreckage disclosed that the failure was due to negligence in sewing a seam on one of the fabric-covered wings, and therefore a decision was made to proceed with the second prototype, designated IK-2. The second prototype had metal-skinned wings and a shallower cooling radiator. The IK-2 was ready for test in June 1936. A new test pilot, Dobnikar, performed the preliminary flight tests, including a mock battle against a Hawker Fury, a biplane, flown by Captain Bajdak. The IK-2 outperformed the biplane in all respects, thereby confirming the hopes of the young designers.

Operational history

Based upon results of preliminary testing, the Royal Yugoslav Air Force ordered a production batch of 12 IK-2 fighters, which were all delivered in 1937. When German forces invaded Yugoslavia on 6 April 1941, the only unit of the Yugoslav Air Force armed with the IK-2 was the 4th fighter regiment, composed of 33rd and 34th air force groups stationed at Bosanski Aleksandrovac airfield, in northwest Bosnia. The 4th fighter regiment was equipped with 18 Hawker Hurricanes and eight Ikarus IK-2 fighter aircraft.
Rovine airfield, situated north of Banja Luka, was the base of the Yugoslav 8th bomber regiment and its 24 Bristol Blenheim I bombers. During a German attack on the base on 7 April, five IK-2s together with five Hawker Hurricanes engaged German Messerschmitt 109 fighter aircraft. In the ensuing dogfight, the Yugoslav fighters managed to repel the 27 attacking German fighters, destroying two in the process at the cost of two Hurricanes and one IK-2 [1]. For the rest of the short conflict IK-2s were used for strafing advancing German columns and on several occasions they scrambled in pursuit of German reconnaissance aircraft, but to no effect. At the end of the brief campaign the four surviving IK-2s were overhauled at the Ikarus aircraft plant in Zemun before being transferred by the Germans to the newly formed Air Force of the Independent State of Croatia.

Further Development

A proposed development of the IK-2 was the IK-4, a two seat reconnaissance monoplane, but it was never ordered.

Variants

• IK-1L : First prototype.
• IK-02 : Second prototype
• IK-2 : Single-seat fighter aircraft.
• IK-4 : Proposed two-seat reconnaissance aircraft. Not built.

Operators

 Kingdom of Yugoslavia

• Yugoslav Royal Air Force

 Independent State of Croatia

• Zrakoplovstvo Nezavisne Države Hrvatske

Specifications (Ikarus IK-2)

General characteristics

• Crew: one, pilot
• Length: 25 ft 10 1/4 in (7.88 m)
• Wingspan: 37 ft 4 4/5 in (11.40 m)
• Height: 12 ft 7 1/8 in (3.84 m)
• Wing area: 193 3/4 ft² (18.00 m²)
• Empty weight: 3,311 lb (1,502 kg)
• Loaded weight: 4,094 lb (1,857 kg)
• Powerplant: 1× Hispano-Suiza 12Ycrs liquid-cooled V12 engine 3-bladed, adjustable pitch, 860 shp (642 kW)

Performance

• Maximum speed: 270 mph at 16,400 ft (435 km/h at 5,000 m)
• Cruise speed: 155 mph (250 km/h)
• Range: 435 miles (700 km)
• Service ceiling: 39,400 ft (12,000 m)
• Wing loading: 22 lb/ft² (107 kg/m²)
• Power/mass: 0.21 hp/lb (0.35 kW/kg)

Armament

• 1 × 20 mm Hispano-Suiza HS.404 cannon with 60 rounds
• 2 × 7.92 mm Darne machine guns

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