Tag Archives: Ikarus

Ikarus IK-2

WW2, Yugoslavia, , ,

kingdom of yugoslavia flag Yugoslavia (1933)
Fighter – 2 Prototypes & 12 Production Aircraft Built

The IK-2 fighter aircraft. Source: www.vazduhoplovnetradicijesrbije.rs

During the early 1930’s, the Royal Yugoslav Army Air Force (RYAF) was mainly equipped with old and obsolete biplane fighters. The introduction of a new fighter was desirable, but its development was hampered by the resistance of leading military officials, and pilots who still believed in the superiority of the biplane. Once Ikarus commenced production of the new high-wing IK-2, it readily demonstrated its superiority over the biplanes of the prior generation.

History of Ikarus 

Ikarus was one of the first Yugoslavian domestic aircraft manufacturers. It was formed in October 1923 by a group of businessmen from the city of Novi Sad. The aircraft development department was led by Josip Mikl and Dimitrije Konjević. Josip Mikl had previously been involved in the development of hydroplanes for the Austro-Hungarian Empire during World War I, while Dimitrije Konjević was a former high-ranking officer in the Yugoslav Naval Air Force. The company saw success during the twenties and received a series of new orders for the production of aircraft, mostly for training. In 1927 thanks to increasing revenues, Ikarus opened a new production plant located in Zemun near the capital of Belgrade. It was heralded as a great success when it received a large production order for some 200 license-built Potez 25 aircraft in 1932.

Ikarus crest. Source: Wiki

The IK-2 Development

In early 1930, the main fighter of the RYAF was the aging Avia BH-33 biplane fighter. In the hopes of replacing it with a new domestically-developed fighter, two aircraft engineers from Ikarus, Ljubomir Ilić, and Kosta Sivčev began working on a new design. Interestingly this was a private venture and not ordered by the state, which was unusual.

While initially intended to be a low-wing fighter with retracting landing gear, due to fierce opposition from many Air Force officers and pilots who favored the old biplane design, this new concept had to be abandoned at an early stage of development. The two engineers then decided to proceed with a high-wing fighter design that was to be powered by a strong engine. A wooden mock-up was completed in 1933 which would be tested using a wind tunnel in Paris. After the first drawings and testing of the mock-up were completed, the result of this work was given to the RYAF officials in September 1933. After an analysis of all available data, a green light was given for the project, and Ikarus was instructed to build the first prototype.

At this early stage, the new fighter received the IK-L1 designation. As was common in Yugoslavia at the time, new aircraft designs usually received a designation based on the designer’s initials. In this case, I stand for  Ilić and K stands for Koča which was Kosta Sivčev nickname. The L1 represents L for Fighter (Lovac in Yugoslavian) and the number 1 indicates the first prototype. The first fully functional prototype was completed by September 1934.

The first prototype IK-L1 with its two designers Ljubomir Ilić and Kosta Sivčev next to it. Source: www.vazduhoplovnetradicijesrbije.rs

Testing the First Prototype

While the IK-L1 prototype was scheduled to be flight tested shortly after the first prototype was fully completed in September 1934, due to numerous delays it wasn’t conducted until April 1935. Unfortunately for the Ikarus and its design team, the first prototype had a very short and abrupt service life. As it was being prepared for the first series of test flights, an upswell of opposition, mainly from Captain Leonid Bajdak and other pilots, vehemently objected to the introduction of such a radical new design, arguing that the biplanes were superior. Regardless, Bajdak was chosen to fly test the IK-L1 prototype.

The maiden flight was made on the 22nd of April, 1935 at an airfield near Belgrade in Zemun. The first day of flying was rather successful, with the prototype exhibiting generally good performance. The test the following day produced largely similar results, but upon landing, some of the wing’s fabric skin was noted as slightly loose. Regardless, it was agreed that the testing should carry on. On the 24th of April, while flying the prototype, Captain Bajdak performed a series of unplanned aerobatics. At a height of 1,000 meters, he made a sharp dive, followed by an abrupt climb. This of course caused massive stress on the wing, which led to part of it breaking off the aircraft. Bajdak lost control and had to bail out. While he survived without injury, the IK-L1 prototype crashed and was completely destroyed.

According to Captain Bajdak in his report, he wrote that the IK-L1 had good controls and was pleasant to fly. The most obvious issues were the lack of visibility, due to the high-wing design. Another of his objections was the long take-off of some 300 meters. This was a surprisingly fair report from a pilot who professed such serious misgivings about this new design.

Work on a New Prototype

After an analysis of the IK-L1 wreckage, it was discovered that the accident was primarily due to poor build quality. As Captain Bajdak’s report was insufficient to make a final conclusion, Ikarus officials decided to produce another prototype. This time great care was taken to ensure the overall quality of its construction. Another change made was that the aircraft was built using mostly metal construction, with the exception of the aft fuselage and tail. The second prototype was designated IK-02 and took about ten months to be built, completed in June 1936. A new test pilot was chosen, Flight Lieutenant Janko Dobnikar. The series of flight tests were carried out at the newly opened test center stationed at the Zemun airfield. Early flight tests were quite satisfactory, with the IK-02 reaching a top speed of 435 km/h.

In 1937 the IK-02 prototype was tested in a mock dogfight against the Hawker Fury, the RYAF’s then-current biplane fighter. After a series of 16 such exercises, the IK-02 easily beat the Hawker Fury in almost every category of flight performance,  speed, climb rate, and turning ability, among others. Frustrated by the success of the new fighter, Captain Bajdak and Lieutenant Dobnikar frequently got into fierce quarrels. It ended with Lieutenant Dobnikar challenging Captain Bajdak to a flight contest. The conditions of the contest were as follows: both pilots had to reach a height of 4 km over Zemun, after which they were to race a distance of 140 km from Belgrade to Novi Sad and back. The competition was meant to end in a mock dogfight between the two. Lieutenant Dobnikar IK-02 easily won the first two rounds of the race. The mock dogfight was fierce but Captain Bajdak’s Fury was constantly overtaken by the superior IK-02. In the end, he had to admit defeat and thus concede that the IK-02 had bested the biplane. Unfortunately, the IK-02 would be lost when it was hit by lightning during a flight. As the aircraft began to catch fire, the pilot bailed out. While he survived, the aircraft crashed and burned, completely destroying it.

Limited Production

Despite both prototypes being lost to separate accidents, their overall performance was deemed acceptable and a small production order was given. In November 1937 Ikarus was instructed to produce 12 IK-2 aircraft. The first six were delivered in December 1938, with the remaining aircraft arriving by February the following year. After a brief period of adjustment and training, the IK-2 was allocated to the 6th Fighter regiment stationed in Zemun. In October 1939, the IK-2 was redeployed to Zagreb and given to the 4th Fighter Regiment. Just prior to the Yugoslavian entry into World War II, the 4th Fighter Regiment would be repositioned to Bosanski Aleksandrovac close to Banja Luka. It was part of the 107th Squadron with the task of protecting the 8th Bomber Regiment, consisting of some 23 Bristol Blenheim bombers.

Despite being superior to other fighter designs that were in service with the RYAF, it too would be replaced by the later developed IK-3 fighter. Source: www.destinationsjourney.com

Technical Characteristics

The IK-2 was a high-wing, single-engine, almost all-metal fighter aircraft.  Its fuselage was constructed of a chrome-molybdenum steel tube frame which was then covered with duralumin skin. The rear section of the fuselage close to the tail unit was covered with fabric.

The semi-cantilever wings were built using the same principle as the fuselage. The difference was that the first prototype used a fabric skin. The second prototype and the production aircraft used a duralumin skin. Two larger struts were placed beneath each wing. The tail unit was of a standard design, with one horizontal and two vertical stabilizers.

Close-up view of the IK-2 wing struts construction. Source: N. Miklušev Maketar Plus

The fixed landing gear consisted of two larger wheels and a smaller tailwheel. To help during landing the front landing gear was equipped with pneumatic shock absorbers. These were also fitted with brakes. The tailwheel was steerable. Initially, the front landing wheels were covered in a protective cover, also known as ‘spats,’ which were later removed.

The cockpit was fully enclosed. Interestingly its sliding canopy actually slid down into the fuselage sides. Quite similar to those used on ordinary cars. Due to the high wing design, the pilot’s visibility was severely limited. To somewhat remedy this issue two small glass windows were placed on the cockpit fuselage sides to help during landing.

The IK-2 cockpit was fully enclosed, but its sliding canopy slides down into the fuselage sides. Source: N. Miklušev Maketar Plus
To help the pilot cope with the cockpit’s fairly limited visibility, two smaller glass windows were placed on the cockpit fuselage sides. Source: N. Miklušev Maketar Plus

The two IK-2 prototypes were powered by an 860 hp Hispano-Suiza V-12 engine. It was equipped with an adjustable pitch three-blade propeller. The fuel tanks were located just aft of the engine in front of the cockpit. The production aircraft was powered by an 860 hp Avia HS engine. This engine was built under license in Yugoslavia. Overall performance of the aircraft did not change much, as the engine swap was mainly done to facilitate ease of maintenance.

The IK-2’s armament consisted of two 7.7 cm Darne Mle 1930 machine guns, and one 20 mm Hispano HS-9 cannon. The machine gun’s ammunition load consisted of 250 rounds each, and 60 rounds for the cannon. The cannon fired through the center of the propeller shaft, while the two machine guns were placed on each side of the front of the fuselage. Some IK-2’s had their cannon replaced with a 7.92 Browning machine gun. But by the time of the war, all available aircraft were equipped with the 20 mm cannon.

According to D. Babac, the two Darne Mle 1930 machine guns were at some point replaced with two 7.92 Browning machine guns. In addition, this author notes that the machine guns were placed above the engine compartment and not on the sides.

In War

When the war broke out on the 6th April 1941 the 4th Fighter Regiment had only 8 fully operational aircraft ready for service. Four IK-2’s suffered from mechanical breakdowns and were undergoing repairs at Zemun and Zagreb workshops. Author Z. Rendulić mentioned that only 10 IK-2 were available.

Two IK-2 (With 31 and 34 white painted markings) from the 4th Fighter Regiment were taken at Borongaj airfield in Zagreb in 1940. Note the long groove for the machine gun located above the exhaust pipes. Source: N. Miklušev Maketar Plus

In addition, the 4th Regiment had 18 to 20 Hawker Hurricanes, making this unit among the most up-to-date in the RYAF. On the first day of the war, the IK-2 was mainly used for reconnaissance. The following day, two IK-2s tried to bring down a German reconnaissance aircraft but failed to do so. One IK-2 would be lost, possibly due to mechanical breakdown. The first proper combat engagement of the IK-2 occurred on the 9th of April when during reconnaissance, a group of some 23 Bf 109 were spotted.  While one IK-2 had to land to refuel, the second one provided a delayed action in hopes of giving the 4th Fighter Regiment enough time to muster its available fighters. Shortly after, some 5 or 6 IK-2 and 8 Mk.I Hurricanes joined the fight. The German fighters were attacking in well-coordinated groups, protecting each other, while the Yugoslav fighters entered the battle in a somewhat disorganized manner. After a fierce skirmish that lasted some 10 minutes, the Germans broke off and retreated back to their base of operations in Austria. The Germans lost two aircraft, while the Yugoslavians lost three, one IK-2 and two Hurricanes.  In the next few days, engagements with the enemy were rare, but the IK-2 managed to shoot down one Ju 88, in addition to two other Luftwaffe aircraft.

The 4th Regiment would meet its fate on the 14th of April when the pilots decided to destroy their remaining aircraft in order to prevent them from falling into enemy hands. Despite their attempts, the Germans managed to capture one slightly damaged IK-2 belonging to the 4th Fighter Regiment. Four additional aircraft were acquired when the repair workshops in Zagreb and Belgrade were captured.  Some internet sources noted that up to 9 aircraft were captured by the Germans, but this seems highly unlikely and that the number of 5 is probably correct.

While a number of IK-2 were lost due to mechanical failures, the majority would be destroyed by their own crews to prevent them from being captured by the Germans. Source: www.destinationsjourney.com

In NDH Service 

Following the defeat of Yugoslavia, the Independent State of Croatia, a German puppet state was created. In June 1941 a request was made to the Germans to provide over 50 captured Yugoslavian aircraft including the IK-2, in an attempt to create a Croatian Air Force. The Germans were more than willing to give the most obsolete aircraft including four IK-2. The fate of the fifth aircraft is not clear. It may have been cannibalized for spare parts, or even sent to Germany for evaluation, but due to a lack of precise sources, we can not be sure. The Croatian Air Force regularly had problems acquiring spare parts for the Yugoslavian aircraft, as these were either destroyed, sabotaged, or commandeered by the Germans. Surprisingly the IK-2 remained in service for a few years until 1944 when they were finally withdrawn from service. They were rarely used by the Croats who often complained about its poor visibility.  Sadly no IK-2 survived the war, with all likely being scrapped.

Production Versions

  • IK-L1 –  First prototype aircraft that was lost in an accident only a few days after initial trials were conducted
  • IK-02 – The second more successful prototype
  • IK-2 – Production version

Operators

  • Kingdom of Yugoslavia – Eight were used during the April War.
  • Independent State of Croatia NDH – Used four aircraft supplied by the Germans, their service was limited.

Conclusion 

The Ikarus IK-2 was one of the earliest Yugoslavian attempts to develop the first proper fighter aircraft and was intended to replace the aging biplanes then in service with the Yugoslavian Royal Air Force.  While it proved to possess superior performance to biplane fighters, it too was quickly made obsolete by the introduction of new low-wing fighter aircraft. Regardless, the IK-2 was a sound design, which proved that the Yugoslav aviation industry, despite its small size, was capable of producing a viable mono-wing fighter aircraft.

The Ikarus’ powerful engine and impressive armament paved the way for Yugoslavia’s later advanced monoplane, the IK-3. Its performance in key areas gave it an advantage over the Hawker Fury. The IK-2 saw combat against Germany’s advances in the early 1940s before it was ultimately superseded by more advanced aircraft.

IK-2 Specifications
Wingspans 11.4 m / 37 ft 4 in
Length 7.88 m / 25 ft 8 in
Height 3.84  m / 12 ft 6 in
Wing Area 18  m² / 59 ft²
Engine One 860 hp Avia HS12YCrs
Empty Weight 1.500 kg / 3.300 lbs
Maximum Takeoff Weight 1.875 kg / 4.130 lbs
Climb Rate to 5 km In 5 minute 25 seconds
Maximum Speed 450 km/h / 280 mph
Cruising speed 250 km/h / 155 mph
Range 700 km/ miles
Maximum Service Ceiling 12,000 m / 39.370 ft
Crew 1 pilot
Armament
  • Two 7.7 mm machine guns and one 2 cm cannon
Yugoslav IK-2 107 Eskadrila, 34 Grupa, 4 Lovački Puk No.2104
Yugoslav IK-2 107 Eskadrila, 34 Grupa, 4 Lovački Puk No.2108
IK-2 in NDH service

Credits

  • Written by Marko P.
  • Edited by Henry H. & Ed J.
  • Illustrated by Ed J.

Sources

  • T. Likos and D. Čanak (1998) The Croatian Air Force In The Second World War, Nacionalna i Sveučilišna Knjižnica Zagreb
  • V. V. Mikić (2000) Zrakoplovstvo nezavisne države Hrvatske 1941-1945, Target Beograd
  • Č. Janić i O. Petrović (2011) Kratka istorija vazduhoplovstva u Srbiji, Aero Komunikacije
  • D.Babac Elitni vidovi Jugoslovenske vojske u Aprilskom ratu.
  • Z. Rendulić (2014) Lovačka Avijacija 1914-1945, Teovid
  • B. Dimitrijević, M. Micevski and P.  Miladinović (2016) Kraljevstvo Vayduhoplovstvo 1912-1945
  • N. Miklušev (2013) Maketar Plus, IMPS Srbija
  • http://www.vazduhoplovnetradicijesrbije.rs/index.php/istorija/565-ikarus-ik-2

 

Ikarus 214

Cold War, Yugoslavia, , ,

Yugoslavia flag Federal People’s Republic of Yugoslavia (1948-1967)
Multi-Role Twin Engined Aircraft – 23 Built

The Ikarus 214 [otpisani.niceboard.com]
After World War Two, the new Communist Yugoslavian Air Force Command began a long process of restoring the destroyed aviation industry. The first attempts were made in the late 1940s, when several new and experimental designs were built, including the Ikarus 214. While most of these would remain prototypes or be built in small numbers, they would serve as a base for future developments and the experience gained would be used in the following years.

History

The first steps towards rebuilding the new Communist Yugoslav aviation industry were made during the war on 24th October 1944. Negotiations with representatives of many pre-war aircraft manufacturers about the possibility of reviving the devastated aircraft industry were held at Zemun near the capital city of Belgrade. Many pre-war aircraft industry designers and engineers would survive the war, and would be used to form the base of the future Yugoslav aviation industry.

Ikarus 214 D Prototype in Flight [paluba.info]
Two years later (23rd February 1946), the Aeronautical Technical Institute created a competition for the development of four new designs. One was for a flying school and tourism aircraft, while the others were for a two-seater basic trainer, an advanced trainer, and a multi-seat trainer version that could potentially be used as a transport plane. The Aeronautical Technical Institute was a pre-war institution which was responsible for placing orders and monitoring new aircraft development. During the period of 1947 to 1952, several different designs, including the maritime role, what would become the Ikarus 214, were produced. 

Constructor Group No.5, under the leadership of the aircraft engineer and professor Sima Milutinović, received orders to design a light two-engined transport and bomber crew trainer aircraft under the military designation 214. After the calculations and drawings were completed, the production of the first prototypes began in 1948 at the Ikarus factory. By 1949, two prototypes were completed and were designated 214P and 214D.

Name

The original military designation of this plane was simply 214. After the first two prototypes were built, the manufacturer’s name, Ikarus, was added to the designation. However, some sources call it the type 214 or simply the 214. This article will use the 214 designation for the sake of simplicity.

Technical Characteristics

The 214 was designed as a low wing, twin engine, mixed construction plane. Despite being primarily intended as a transport and trainer plane, the 214’s fuselage was designed to be able to withstand bomber duties. The fuselage had an unusual design and was built by combining two monocoque “sandwiches” (two light skins placed around a thick core) shell construction (same as on the British de Havilland Mosquito which was in use with the Yugoslavian Air Force.) The 214’s fuselage was large and had plenty of room for use as a transport or passenger aircraft.  The 214 passenger version had 7 seats placed behind the pilot’s cockpit. On both sides of the fuselage, there were two rounded and two elongated windows. The 214 (except the later built 214PP and AM-2) had a large and fully glazed round shaped nose with good all round forward visibility.

The Improved 214AM-2 Anti-Submarine Variant
The 214 prototypes were powered by the weaker Ranger SVG-770C engines.

The wings were made of wood and consisted of two box shaped longerons. The whole wing was covered with birch glue. The twin tail vertical and horizontal stabilizers were also made of wood. The rudder and the elevator were made of duralumin and covered with canvas.

The first engine used by the two prototypes was the air-cooled Ranger SVG-770C providing 520 hp, with the two-bladed Hamilton standard type propellers. The second prototype, and all subsequent aircraft were equipped with the stronger nine-cylinder air-cooled Pratt & Whitney R-1340-AN-1, which delivered 600 hp. Four fuel tanks were placed in the wing longerons, with a total fuel load of 780 liters (206 gallons.) The 214 used B-95 gasoline as its main fuel.

The Ranger SVG-770C Engine [vazduhoplovnetradicijesrbije.rs]
The landing gear retracted (except on the first prototype) into the rear engine nacelles but was not completely covered. The rear tail wheel was fixed but was provided with a brake system. The landing gear was hydraulically driven.

The pilot’s cockpit was positioned above the front fuselage and provided a good all-around view. In the cockpit there were positions for two crew members (pilot and assistant) and dual controls which were connected with the rudders and elevators with wire. However, this flight control system was flawed, because it took a few seconds before the plane responded to the command given by the pilot, for example during turns, climbs, or descending maneuvers. This made the 214 particularly difficult to fly during harsh and bad weather. 

The front glazed nose provided a good all around forward view.

Inside the cabin were several flight instruments, such as the airspeed and altitude indicators (type Teleoptik 456-6 and 452, the 214AS version had two altitude indicators), two variometers (type Teleoptik 26B), a turn and slip indicator (type 441-0), a horizontal situation indicator (type Teleoptik 32C, the 214AS version was equipped with two), a magnetic compass (type 443-0), two engine tachometers, fuel and oil gauges, landing gear indicator, and thermometer. Additional equipment for the crew’s safety included parachutes, fire extinguishers, oxygen bottles, and heating & ventilation. In the first series of aircraft produced in 1958, a SCR-522 radio unit was installed This radio had 8 watts of power with a range of 50-290 km (30-180 mi) depending on altitude. The 214F version was equipped with a Rudi Čajevac radio-telephone.

One of the prototypes was armed with three 7.92 mm MG-15 machine-guns, one forward fixed, one on the side (not specified whether  it could be aimed) and one in the rear facing turret. The decision to use older captured German MG-15s was most likely based on the fact that the 214 was to be used as a trainer aircraft, with better and more modern armament reserved for front  line aircraft. The 214 could also be equipped with a bomb load of four 50 kg (110 lb) bombs. Weapons were rarely installed on the production versions, as they were used mostly for transport.

First Test Flights

The 214 made its first flight on 7th August 1949, at the Zemun airfield near Belgrade. Immediately, there were problems with the lack of an adequate retractable landing gear. As a temporary solution and to speed up the testing process, the engineers simply reused the landing gear from an Il-2 (which was in use by the Yugoslav Air Force), but for technical reasons it was not retractable and remained fixed. There were also problems with inadequate propellers, as the 214 prototypes had to use propellers designed for a single engine aircraft. Despite the fact that it was never intended to be used with a fixed landing gear, military officials demanded that the flight tests begin as soon as possible. During its first test flight, one of the two engines simply stopped working. The pilot made a turn back towards the airfield, but the 214 could not maintain altitude and the plane crashed killing the test pilot Lieutenant Sima Nikolić.

An investigation that was subsequently conducted found that the fixed landing gear and the poor choice of propellers created too much drag. The single working engine could not overcome this drag. In addition, the vertical tail surfaces proved to be inadequate.

Prior to this accident, the engineers and designers predicted, at least in theory, that the 214 could maintain a constant altitude with only one working engine. In case of such a scenario, the test pilots were instructed to fly to the large and open Borča field,  Belgrade, and land there. Why the pilot decided to return to Zemun airfield instead of proceeding to the instructed field was impossible to determine. Despite this accident, the development of the 214 would go on.

The second prototype was fully completed by December 1949. In order to avoid accidents, the second prototype spent almost two years being redesigned and tested. Unfortunately, there is no information about any flights made during this period, but it is possible that some were conducted. This plane received larger vertical tail surfaces and a new landing gear. More intense flight tests were made from 1951 on. During this time, different trainer configurations were tested. These were basic training variants with three crew members and no armament, a bomber training variant with four crew members with up to three machine guns and bombs, and as a passenger transport variant with two crew members, six passengers, and no armament.

The Pratt & Whitney R-1340-AN-1 became a standard production engine on the 214. [vazduhoplovnetradicijesrbije.rs]
During 1954 and 1955, the second 214 prototype was equipped with Pratt & Whitney R-1340-AN-1 engines. It made its first flight with these engines on the 16th of September 1955 without any problems. In 1957, the second prototype was modified for use as a photo-reconnaissance aircraft (serving as the basis for the later 214F variant). This prototype would be used in this role until September of 1959, when the plane was lost in an accident. 

In 1955, it was decided to put the 214 into limited serial production. It  began in 1957 (or 1958 depending on the sources) and, by the time it ended in 1960, a total of 21 (or 20 depending on the source) 214 planes were produced. 

Anti-Submarine role

In 1958, a decision was made by the Yugoslavian Air Force for the adaptation of the 214 for anti-submarine operation. The first series of 214s produced was allocated to the 97th Air Regiment (this unit was renamed into the 97th Anti-Submarine Regiment in November 1958). The first group of pilot officers from the 97th Air Regiment was moved to Zemun airfield for training on the 214 in October 1958. All pilots from the 97th Air Regiment (which was equipped with British de Havilland Mosquitos) completed training by July 1959. In the period of 1959 to 1960, there were 41 pilots in training, but the number was reduced to 25 in 1961 and 1962. The entire training process was carried out under the leadership of World War II veteran Captain Okanović i Semolić.

As the 214 lacked any equipment for anti-submarine operations, it could be used only in reconnaissance missions, and only weather permitting where visibility was good. In 1960, there were plans to improve the 214’s anti-submarine performance by adding the necessary equipment. One modified aircraft, under the new 214PP (No. 61004) designation, was tested by Captain Petar Savić on the 6th of May 1960. Two years later, a new anti-submarine version, 214AM2 (No.61015), also known as 214M-2, was tested in June 1962 by pilot Aleksandar Prekrasov. Both versions had a fully enclosed nose instead of the standard glazed one (the sources are not clear, but it appears that other 214  were also equipped with an enclosed nose). In addition, the 214AM2 was provided with a radar placed below the front nose. However, this improved version was still not up to the task of anti-submarine duties. Even if the crew spotted an enemy submarine, it could hardly do anything. Due to equipment delays, more extensive testing was not possible before 1963. The 214AM2 was tested in Batajnica (near Belgrade) and later in Pula on the Croatian coast. The tests of the 214AM2 were completed by 1965, and the results of these tests assessed the variant as partially successful. 

Even before these tests were completed, in May 1964, by the order of the Secretary of National Defense, the 97th Anti-Submarine Regiment was reorganized as 97th Auxiliary and Support Regiment and supplied with C-47 transport planes. The 214 was still in use with this unit but mostly in a transport role. This decision to remove the 214 from the anti-submarine role was based on the fact that they were not sufficiently equipped, and could not effectively engage submarines. The 214 would be used by this unit up to 1966, when they were removed from service.

The 214F 

Front view of the 214F version.

In 1960, three aircraft, designated as 214F, were built in the Ikarus factory to be used as photo-reconnaissance planes. The main difference was the removal of the seats inside the plane’s fuselage and replacing them with positions for a cameraman, his assistant, and  camera equipment. 

Limited Operational Service Life

Despite being designed to fulfill several different roles, the 214 (beside the two anti-submarine modifications) was mostly used as a light transport and sometimes for day and night bomber crew training. The aircraft that were used in this role received the 214AC or 214P designations and, in total, 18 were built of this version. The basic transport and training variant had 7 seats placed behind the cockpit, with four on the right, and three on the left side. In some sources, the passenger number is listed as 8. The idea to use the 214 as a light bomber was rejected due to the rapid development of more advanced fighter-bombers. The 214 had many technical problems during its operational use, such as inadequate radio equipment, problems with the control of the wing flaps, inadequate electric equipment for night flights, and cracks that would appear in the propeller spinners after extensive use. 

A parachute group in front of a 214 prior to take-off. [vazduhoplovnetradicijesrbije.rs]
Rear view of a 214. The Yugoslav flag (blue, white and red with a red star in the middle) was often painted on the tail. [otpisani.niceboard.com]

The 214 was mostly used by the Yugoslavian Air Force as a transport plane.

In Civilian Service

By 1966, only six 214 transport versions were still operated by the Yugoslavian Air Force. The next year, these six were withdrawn from service and given to the Aeronautical Association of Yugoslavia for use. They were registered as passenger planes with two crew members and seven passengers. These received the following civilian markings based on their stations: YU-ABN in Ljubljana, YU-ABO in Vršac, YU-ABT in Novi Sad, YU-ABS in Zagreb, YU-ABR in Sarajevo and YU-ABP in Skopje.

In 1968, only four were listed as operational and, by 1970, they were removed from the civilian registers. While they remain stored, some parachute flights were carried out after 1970. In the following years, all except one were scrapped. This aircraft (No.60019) was given to the Yugoslav Aviation Museum near the Capital of Belgrade in 2001. The plane is in a poor state of repair and is waiting for restoration. Due to the financial difficulties of the museum, there is only a small chance that it will be restored in the near future.

This is a civilian 214 stationed in Sarajevo. [paluba.info]
The only surviving 214 (No.60019) aircraft can be seen in the Belgrade Aviation Museum. [Wikipedia]

Production Run

As previously mentioned, the decision for the production of the 214 was made in 1955. By the time the production ended in 1960, a small series of 21 aircraft was produced (excluding the two prototypes.) Many sources state that around 20 were built but, according to Č. Janić. and O. M. Petrović, 21 were built (18 214AC and 3 214F). The problem with determining the exact number of produced aircraft lies in the fact that, in some sources, the three produced 214F include the prototype which was modified for this role. Despite the fact that the production began during 1957 (by Ikarus), the whole process was slow and, by the 1st of January 1959, only six 214 were built. Only one was built in 1957 and an additional five during 1958. By January 1st 1962, there were 21 aircraft in service with the Yugoslavian Air Force, with 17 fully operational. In the following years, there were no accidents and an average of between 15 and 18 were fully operational at any given time. In order to increase the 214’s operational service life, one additional factory (Vazduhoplovno-Tehnicki Remontni Zavod) was opened in Zagreb for the production of spare parts and repairs. The Ikarus factory, due to its  involvement  in other projects, was  exclusively involved in the production of spare parts from 1962 to 1964.

Due to the small numbers built, the 214 had only a few different variants.

  • 214P and 214D prototypes – Two prototypes built and tested with different engines.
  • 214F – 3 built as photo-reconnaissance planes. 
  • 214AC (214P) – Main production version. 18 were built as trainer/passenger planes.
  • 214PP – One production aircraft was modified for anti-submarine operation.
  • 214AM-2 – One production aircraft was modified as an improved anti-submarine variant.

Conclusion 

Despite not being a successful design, the 214 did see operational use in the Yugoslav Air Force. As only small numbers were built, the model’s role was limited. The 214’s greatest success was that it helped rebuild the destroyed Yugoslavian aircraft industry and the designers and engineers gained additional experience in working with more modern aircraft designs.

Ikarus 214 Specifications
Wingspan 53 ft 2 in / 16.2 m
Length 38 ft 9 in / 11.2 m
Height 13 ft  / 3.95 m
Wing Area 320 ft² / 29.8 m²
Engine Two nine cylinder air-cooled P&W R-1340-AN-1 with 600 hp
Empty Weight 3,740 lbs / 3,970 kg
Maximum Takeoff Weight 11,080 lbs / 5,025 kg
Fuel Capacity 780 l
Maximum Speed 227 mph / 365 km/h
Cruising speed 186 mph / 300 km/h
Range 670 mi / 1,080 km
Maximum Service Ceiling 23,000 ft / 7,000 m
Crew One pilot and One copilot
Armament
  • Three 7.92 mm MG-15 Machine Guns
  • Bomb load of four 50 kg bombs

Gallery

Illustrations by Carpaticus

Ikarus 214
Ikarus 214AM-2 Anti-Submarine Variant
Ikarus 214 in Civilian Service

Credits

 

Ikarus MM-2

WW2, Yugoslavia, ,

Yugoslavia flag Yugoslavia (1939)
Prototype Advanced Trainer – 1 Built

The MM-2 prototype had an unusual color scheme with a combination of red and polished aluminum.

With the emergence of new fighter planes in the years leading up to the Second World War, it became necessary to replace the older biplane trainer aircraft, which were too slow, in order to efficiently train new pilots to fly the newest fighters. Thus, it was logical that more modern advanced trainer aircraft would be needed. The MM-2 was an experimental Yugoslavian solution to this problem.

First Steps

At the end of the thirties, the Yugoslav Air Force was equipped with modern planes, such as the German Me-109, the indigenous IK-3, and the British Hurricane, highlighting the need for an updated trainer. There were several older aircraft in use for the role, like the FP-2 and the Rogožarski PVT, with a maximum speed of around 140 mph (230 km/h) but there was a need for a much faster and modern aircraft trainer.

The designer of the MM-2 trainer, Captain Dragutin Milošević.

To fill this gap, Air Force engineer and pilot Captain 1st Class Dragutin Milošević, on his own initiative, began to work on a new advanced trainer in 1936. The first aerodynamic calculations, choice of engine, structure, and the design were done by 1937. This new plane was conceived as a two-seater with seats one behind the other, with an enclosed cockpit and dual controls. It had a low wing, mixed construction, with a single engine and retractable landing gear. The engine would have been the Renault 6Q-02, giving 162 kW (220 hp). Milošević never gave a designation for this plane, but was later simply named the M-1.

Captain Dragutin Milošević submitted this project to the Yugoslav Department of Aviation in 1937. The Department analyzed this proposal and, while on paper it would have had great flying performance, a decision was made to reject it because the parts necessary for its construction had to be imported from abroad.

This decision did not discourage Captain Milošević, and he made attempts to improve his design. He proposed replacing the Renault with the license-built Gnome-Rhone K-7 309 kW (420 hp) air-cooled 7-cylinder engine. By adding this engine, the length of the plane would be reduced from 23 ft 7 in to 20 ft 4 in (7.2 m to 6.7 m) but the total weight increased to 2,160 lbs (980 kg). To improve the landing characteristics of the aircraft, it would have been necessary to increase the distance between two front landing wheels from 6 ft 2 in to 7 ft 10 in (1.9 m to 2.39 m). All aerodynamic and statistical calculations were finished by 1939. The second version was named M-2 and it was, in essence, the basis of the future MM-2 aircraft.

One wooden model (1:10 scale) was built by the Albatros factory in Sremska Mitrovica. This model would be used to test the aerodynamic properties and accuracy of earlier calculations. Aerodynamic properties were tested in the Paris wind tunnels on the 17th and 18th of July 1939. After these trials, the fuselage length reverted to the original 23 ft 7 in (7.2 m).

Later, Captain Milošević did new calculations that showed that certain changes to the design of the aircraft were necessary. Adding weapons and increasing fuel capacity would lead to an increase of the mass of the M-2 by 242 lbs (110 kg), some 60 lbs (30 kg) in fuel and 176 lbs (80 kg) in armament. After all the other modifications, the total mass reached 2,782 lbs (1,262 kg) compared to the initial 2,160 lb (980 kg). The wing area had to be increased from 129 to 146 sq ft (12 to 13.6 m²) and the wingspan from 27 ft 10 in to 30 ft 3 in (8.5 to 9,23 m).

Adoption of a Prototype

Captain Milošević submitted a letter, together with documents, plans and calculations, to the supreme headquarters of the Yugoslavian Air Force, notifying them of the test results of the proposed M-2 aircraft. Since he did not receive any kind of response, he asked Major Đorđe Manojlović, also an aviation engineer, for help. Although Đorđe Manojlović did not have a direct impact on the design of the M-2, his great influence and connections in the Supreme Air Force Command lead to the continuation of the project. The cooperation of these two men lead to the final approval for construction of the M-2 aircraft project.

The only MM-2 prototype during its construction by Ikarus.

When the Air Force Headquarters of the Army of the Kingdom of Yugoslavia accepted the M-2, construction of this project was given to the Ikarus factory. The contract was signed on the 25th March 1940. It was planned to build one prototype aircraft for testing in order to ascertain if the M-2 was fit to be accepted for serial production. The project was monitored by a team composed of engineer Sava Petrović, Air Force Major Vojislav Popović and the technician Stefan Lazić. The prototype was ready by the first half of November 1940.

Origin of the Name

In the Kingdom of Yugoslavia, there was a custom of using the initials of the names of the designers as the official designation for most of new types of aircraft in service (like the IK-2/3), and MM-2 was no exception. MM comes from the initials of the surnames of Captain Dragutin Milošević and the constructor and engineer Major Đorđe Manojlović. There is sometimes confusion about the exact name of this aircraft. It is sometimes also called MiMa-2. In some documents found after the war, it is also called M.M. 2. In this article, the MM-2 name will be used, as it is the most common.

Technical Characteristics

Captain Dragutin Milošević’s first drawing of the MM-2. Note that the engine nose design appears to be for an inline engine, different from the actual prototype.

The MM-2 was designed as an advanced two-seater trainer, with seats one behind the other, with dual controls and a fully enclosed cockpit. It was a low wing, mixed construction, a combination of wood and metal, single engine aircraft with retractable landing gear.

The wings had a trapezoidal shape with a rounded top. They were constructed by using two racks which were made of steel tubes welded together. The racks were welded to the plane’s hull and the wooden ribs were connected to them by rivets. The wings were covered with canvas, except for the central parts, which were made of aluminum sheet. This was done so that the technicians and repair crews could have easy access to the inside of the wing. The ends of the wings were made of wood that were held in place by steel fittings. The flaps were covered in canvas and operated either manually or hydraulically.

The MM-2 hull was of mixed construction. The main body was made by using welded pipes. The front part was covered with aluminum sheet and the rear with canvas. The tail was made mostly of wood and covered with canvas.

The main engine was the Gnome-Rhone K-7, which supplied 310 kW (420 hp). It was domestically built under license from Franch aircraft manufacturer Rakovica. It was hoped to use a two-bladed metal propeller but, due to the lack of resources, wood was used. The maximum estimated speed (never achieved) was around 250 mph (400 km/h), with an effective range of 475 mi (764 km) with some 40 gallons (150 l) of fuel capacity. Climbing to 6,500 ft (2,000 m) could be achieved in 3 minutes and 9 seconds, but the maximum service ceiling was never adequately tested.

The landing gear was supposed to be of the ‘Nardi’ type imported from Italy, but it was planned to domestically build the landing gears for the production version, to avoid being dependent on foreign countries. On the prototype, no radio was installed but it was hoped to equip all future production aircraft with the FuG VII radios.

The main armament consisted of two wing-mounted 7.7 mm Darn-type machine guns with 175 rounds of ammunition for each gun. The total bomb load consisted of four 10 kg bombs carried under the wings. It must be noted that the armament was never installed on the prototype, as testing was interrupted by the beginning of the war.

First Test Flights

MM-2 Side View

The first test flights were made by the beginning of the 1941 at the Zemun airport. The pilot for these flights was Vasilije Stojanović, the test pilot of the Ikarus factory. By the end of March 1941, some 45 flights had been made with a total of 20 flying hours. The pilot assessed the flying performance of this plane as excellent. The results of these tests indicated that this aircraft had good flight performance. The controls were adequate, both instructor and the students cockpits had enough room with a good field of view and, during flights, the aircraft did not present any tendencies for sudden unpredictable movements. Due to its good air brakes and flaps, take-offs and landings were quite easy. There were no major objections from the test pilot about the MM-2.

The MM-2 could very easily reach speeds of up to 217 mph (350 km/h). The design maximum speed was never tested, but calculations suggested that it could be as high as 250 mph (400 km/h). This was never confirmed due to the outbreak of the war. The MM-2 prototype had an unusual color scheme with a combination of red on most of the rear fuselage and wings, and polished aluminum on the majority of the fuselage and the engine section, with a small Yugoslav flag painted on both sides of the tail.

On the 25th of March 1941, a contract was signed between Ikarus and the Air Force. According to this contract, Ikarus was to prepare for production of MM-2 trainer planes in the near future. Before the production would begin, a last series of tests was to be conducted by a test group at an airfield near city of Kraljevo. An order was given to Stojanović to fly the MM-2 from Zemun to the Kraljevo airfield. Once there, it was planned to do some more flight performance trials in order to examine the limit of the flying characteristics of the MM-2 aircraft. Stojanović completed the flight on the 4th April. Final production was never achieved due to the German invasion of Yugoslavia that started only a few days later.

Operational Service

The MM-2 did not see any active service in the Royal Yugoslav Army because of the beginning of the April war, the German attack on Yugoslavia in April 1941. After the defeat of the Yugoslav army, the Independent State of Croatia, or NDH, was created. In order to form the new NDH military air force, it was necessary to find and obtain planes to equip these new units. Like many other former Yugoslav planes, the MM-2 was also pressed into NDH service in a very limited role.

It seems that the MM-2 had some engine problems (possibly sabotaged) when it was captured by the Germans at airfield near Kraljevo. It is possible that it was in a bad condition since the Germans did not even bother to repair it and put it into operational use.

The MM-2, together with other Yugoslav captured aircraft, was collected and handed over to the NDH. After a while, the MM-2 was repaired under code name No. 6301, and returned to active service. Additional flight tests were conducted by Georgije Jankovski, a test pilot for Dornier-Werke. In September 1941, the plane was transferred to the Zemun airport and handed over to Croatian Major Ivan Pupis for future use. Major Pupis was the leader of the group responsible for the repair, reception and later transfer of all Yugoslavian aircraft captured during the April war. When the MM-2 was repaired and ready for active service, Pupis to keep it for his personal use rather than handing it over to the military.

On the May 13 1942 pilot Vid Saić, he lost control of the aircraft and crashed due to inexperience. The MM-2 was deemed too complicated and expensive to repair.

The MM-2 was ‘owned’ by Pupis until March 23rd, 1942, when he received a direct order from the Croatian Aviation Command to transfer the MM-2 to the ‘Rajlovac’ airfield near the city of Sarajevo in Bosnia. The aircraft arrived at the beginning of April 1942. The MM-2 was given to the 17th Squadron (Jato) which was part of the 6th group (Skupina) under the Command of the Major Romeo Adum. The MM-2 was used mostly for limited test flights. On May 13, 1942 while piloted by Vid Saić (from the 18th Squadron), the plane crashed. The pilot survived the crash with no injuries. A commission was formed to investigate the causes of the crash and found several irregularities: The pilot did not ask for permission and had no orders to fly on the MM-2 that day, and he also did not know anything about the flying characteristics or the condition of the plane. The conclusion was that the pilot was guilty for the accident and, as punishment, Vid Saić lost his Pilot rank. The damage to the MM-2 was estimated to be around 90%. There was no point to try to rebuild it from scratch and the remaining parts were destroyed. There is no information whether it was equipped with any armament in Croatian military service.

Production

Due to the outbreak of war on April 6th, 1941, except for the prototype, no other specimen of this aircraft was ever built. In some documents and letters found after the Second World War, it was discovered that the Ministry of Aviation planned to order around 50 copies of the MM-2 aircraft. Along with this, the Yugoslav military negotiated with Germany for the purchase of Arado Ar 96 training planes, but nothing came of this.

After the war, the new communist Ministry of Aviation and the Ikarus factory representatives were also interested in restarting the production of this aircraft but, as the chief designer had died in one of the many German prison camps and the necessary machines and tools were lost during the war, this was too difficult and was abandoned.

Operators

  • Kingdom of Yugoslavia – Built and tested the single prototype.
  • Independent State of Croatia NDH – Used the MM-2 captured during the April war, but it was lost in an accident.

MM-2 Specifications
Wingspan 30 ft 6 in / 9.23 m
Length 23 ft 7 in / 7.20 m
Height 9 ft 6 in / 2.89 m
Wing Area 14.6 ft² / 13.60 m²
Engine One Gnome-Rhone K-7, 309 kW (420 hp) air-cooled 7-cylinder engine
Empty Weight 1,071 lbs / 894 kg
Maximum Takeoff Weight 2,290 lbs / 1,330 kg
Fuel Capacity 150-160 l
Maximum Speed 250 mph / 400 km/h
Cruising Speed 390 mph / 630 km/h
Range 475 mi / 764 km
Maximum (estimated) Service Ceiling 6,600 ft / 2,000 m
Climb speed Climb to 2,000 m in 3 minutes and 9 seconds
Crew Two, instructor and student pilot
Armament
  • Two Darn M30 7.7 mm machine guns in wings
  • Total bomb load around 40 kg.

Gallery

Illustration by Haryo Panji https://www.deviantart.com/haryopanji

Ikarus MM-2 Side View [Haryo Panji]
MM-2 Front View
MM-2 Rear View

Sources