Unlike Bulgaria, Yugoslavia not only bought aircraft abroad, but also produced its own rather interesting models.
The first steps towards the creation of an air force were taken in 1909, when Serbia bought two balloons. In 1910, foreign pilots flew in Serbia - the first was the Czech pilot Rudolf Simon. A month after Simon, the Russian Boris Maslennikov arrived in Serbia, who in late 1910 - early 1911. performed several flights on his Farman IV biplane, both independently and with passengers. The King of Serbia, Petar I Karadjordjevic, awarded Maslennikov with the Order of St. Sava.
During his stay in France in April 1910, Alexander Karadjordjevic (right), then Prince and heir to the throne of Serbia and later King of Yugoslavia, flew in a Flyer 1 aircraft. Alexander became the first Serb to fly by plane
In 1912, six Serbian officers and sub-officers were sent to study at the Etampes school near Paris. The first of them was an independent flight performed on July 23, 1912 by Mikhailo Petrovich, a pilot, he was awarded a pilot diploma No. 979 of the International Aviation Federation (FAI).
Serbian aviators did not have to wait long for the baptism of fire - the Serbian lands should have been liberated from the Turkish invaders. The pilots were recalled on September 30, 1912, and in preparation for the 1st Balkan War in France, eight aircraft were purchased (three Henry Farman HF.20, three BlerioVI / VI-2, two Deperdissin Type T), and two R. E. P. (Robert Esnault-Pelterie Type F 1912) supplied by France to the Turkish army were requisitioned. The Minister of War of Serbia, Radomir Putnik, by an order dated December 24, 1912, formed an aeronautical team, which included aeronautical and aircraft departments. In addition to Serbian pilots, three French and two Russians arrived in Serbia from France and Russia.
The first Serbian pilot Mikhailo Petrovic
In January 1913, the Russian newspaper Novoye Vremya bought one Farman VII aircraft with its own money, donated it to the Serbian army and sent Russian pilot Kirshtayan with it. In the operation to liberate Shkoder, the Montenegrin troops were assisted by the aircraft of the Serbian "seaside airplane squadron". Three Serbian aircraft took part in the Second Balkan War, making reconnaissance of the positions of the Bulgarian troops.
However, by the beginning of the First World War, Serbian aviation had only 7 worn-out aircraft. Serbia's main allies, France and Russia, initially did not want to supply Serbia with aircraft, giving priority to the supply of their own armies. In the first nine months of the war, the French refused to transfer 12 ordered aircraft to Serbia, although the Serbs had already paid for their construction. Tsarist Russia did not provide aircraft, but it approved a loan in the amount of 6 million rubles for the purchase of aircraft by Serbia in other states.
Nevertheless, the crew of the Serbian plane "Blerio" gave important information for the Serbian army in the battle at Cer. In August and December 1914, they managed to capture several Austro-Hungarian aircraft Lohner B. I BUB, which made forced landings as a result of damage received from artillery fire. The first air battle took place on August 27, 1914. Then one armed Austrian aircraft attacked an unarmed Serbian airplane, but its pilot Miodrag Tomic managed to get away from the enemy. Finally, after 9 months, the French government sent its MF-93 squadron of 12 Farman MF aircraft to Serbia. 11 (5 of them were later donated to the Serbian army) and about 100 military personnel. The first Serbian aviation school was established in 1915, but the difficult military situation in which Serbia found itself prevented its further work. France handed over two not new aircraft "Bleriot" XI, which in Serbia received their own names "Olui" and "Vihor" (storm and whirlwind). The Oluy was the first Serbian combat aircraft - it was equipped with a Schwarclose М.08 machine gun.
Blerio's Oluj aircraft - the first Serbian military (armed) aircraft
In 1915, one Turkish "Blerio" and one Austro-Hungarian "Aviatik" became the trophies of the Serbs. On August 2, 1915, the Serbs performed their first bombing flight. The crew dropped small bombs and arrows on a column of enemy troops. From Russia came two balloons built by the Triangle company and seven artillery batteries, including one anti-aircraft battery with 76 mm cannons. This battery laid the foundation for the air defense of Serbia, shooting down an Austro-Hungarian airplane on August 15, 1915; before the end of the war, the battery shot down two more enemy aircraft. At the same time, several field guns were adapted for shooting at air targets. Due to the dramatic deterioration of the situation in the Balkan theater of military operations, at the end of 1915, the king decided to withdraw his troops from Serbia. After the withdrawal of the Serbian army through Montenegro and Albania to Greece on the island of Corfu, a new air squadron was formed there.
In May 1916, Serbian pilots began flying with five Serbian-French squadrons near Thessaloniki. The squadrons were commanded by a French major, the main task was to support the Serbian ground forces. The revival of the Serbian army was used to train a new generation of pilots, technicians and cadets.
Serbian squadron on the Thessaloniki front
Serbian pilots won their first victory in air combat on April 2, 1917, in a Nieuport aircraft. On the eve of the front breakthrough, the Serbian army had two squadrons with 40 aircraft and Serbian personnel, although not only Serbs served in the squadrons (in particular, there were 12 Russians). Soon, a large number of Russians joined the Serbian army, disappointed with the situation in their own homeland. They were sworn in to the King of Serbia, which did not contradict the previously given oath to serve "for the faith, the king and the Fatherland." The Russians were allowed to continue wearing the military uniform of the Russian Empire. At the beginning of 1918, after completing their training, 12 more Russian pilots and cadets arrived from France. One of the most successful combat sorties of Russian pilots was the flight on September 26, 1918 to attack a column of Bulgarian infantry. One of the pilots was wounded, but the mission was completed in full.
Knowing about the threat of death in his homeland, the king of Serbia invited the Russians to stay in the Serbian army, but many preferred to return to Russia, to Denikin. Later, some of them returned to Serbia.
Until the end of the war, more than 3,000 sorties were carried out. The pilots shot down 30 enemy aircraft, artillery - five more. The commander of the first Serbian aviation squadron later became the first aviation commander of the united state of the southern Slavs.
With the formation of the kingdom of Serbs, Slovenes and Croats after the end of the war, the backbone of the air force of the new state was made up of these forces, in addition to which people from other parts of the newly formed kingdom were recruited into the air force. The material part for the most part consisted of captured Austro-Hungarian vehicles. In early 1919, the Air Force command was formed in Novi Sad, and it was there that one squadron and a pilot school were located. One squadron each was deployed in Sarajevo, Zagreb and Skopje and one flight each in Mostar and Ljubljana.
In the same year 1919, 4 air districts were created, based in Sarajevo, Skopje, Zagreb and Novi Sad. The following year, an aviation department was created under the Ministry of War. The aviation district in Novi Sad was renamed to the 1st aviation command with a fighter squadron, a reconnaissance school, a school for reserve officers (student training), and the aviation district in Mostar to the 2nd aviation command standing out of the pilot school. In addition to this, the 1st and 2nd air commands were attached to the army squadrons.
Since 1922, the Air Force was divided into aviation (reconnaissance, fighter and bomber aviation) and aeronautical (balloons) components.
In 1927, air commands were created at the location of the army districts. Then from the 1st and 2nd air command and the regional air command regiments of mixed composition were formed into 2-3 air groups. In 1930, the regiments were consolidated into air brigades of 2-3 regiments. In 1937, there was a division into flight and non-flight units with the creation of air bases responsible for logistical support. This is how aviation bases of the 1st rank appeared to serve the aviation regiment, the 2nd or 3rd rank - to serve the aviation groups or special squadrons.
In 1923, a decision was made on the need to modernize the JKRV. Biplanes of the First World era had to be replaced with modern aircraft. Many Yugoslav and international companies were involved in the modernization, which made it possible to significantly increase the number of aircraft and the number of flight personnel in a short time. Moreover, both aircraft and licenses for their production were purchased.
The first fighter of the Yugoslav assembly was the French fighter Dewoitine D.1. 79 aircraft were delivered to Yugoslavia in the 1920s, and since 1927 their licensed production was launched at the Zmaj plant in Zemun, which also produced training aircraft from Gourdou-Leseurre and Hanriot under a French license.
Fighter Dewoitine D.1
In 1930, the Yugoslavs bought three Czechoslovakian Avia BH-33E-SH fighters. A little later, the Ikarus plant in Zemun acquired the rights to manufacture it and built 42 machines. They entered service with the Yugoslav Air Force. Some of the VN-33E survived until the German attack on Yugoslavia in 1941.
Fighter Avia BH-33 Yugoslav Air Force
Also under a French license, Zmai produced the Gourdou-Leseurre B.3 fighters (assembled 20 fighters used for pilot training) and Dewoitine D.27 (4 fighters assembled, another 20 delivered from France).
Fighter Gourdou-Leseurre B.3 Yugoslav Air Force
The main light reconnaissance bomber of the Yugoslav Air Force in the pre-war years was the French Breguet 19. The first 19 aircraft were purchased from France in 1924. Another 152 aircraft were received in 1927. In 1928, licensed production began at a specially built state aviation plant in Kraljevo. In total, a total of 425 Breguet 1s were produced until 1932, of which 119 aircraft had Lorrain-Dietrich engines with 400 and 450 hp, 93 - Hispano Suiza with 500 hp, 114 - Gnome - Ron "9Ab, 420 hp, which was made under license in Yugoslavia itself at the plant in Rakovica. 51 Breguet 19-7 aircraft were built with a Hispano Suiza engine with a power of 650 hp., but the motors for them were supplied irregularly, and as a result, about 50 finished cars were left without engines at all. Then the Yugoslavs decided to try to modernize the Br.19 on their own. A group of designers from the Kraljevo plant converted the Br.19.7 to the American Wright GR-1820-F56 Cyclone engine, with a capacity of 775 hp, under the designation Br.19.8. The gliders taken out of conservation were delivered to the Ikarus plant in the city of Zemun, where 48 aircraft were equipped with American motors. The first of them took off in December 1936, the last were handed over to the military in November of the following year. We can safely say that in the second half of the 1920s, the Breguet 19 was one of the best aircraft of its time. However, time takes its toll, and in 1938-40 the Yugoslavs wrote off or transferred to flight schools about 150 "Breguet", mostly of early modifications. However, in April 1941, when German, Hungarian and Bulgarian troops invaded the country, eight squadrons were still flying these machines. Most of the park was both Br.19.7 and Br.19.8, but there were also early modifications.
Yugoslavian light reconnaissance bomber Breguet 19
Along with the Breguet 19, another famous French light reconnaissance bomber Potez 25 with a Gnome-Ron 9Ac Jupiter engine (420 hp) was also in service with the Yugoslav Air Force, which was also produced under license by the Yugoslav company Ikarus. About 200 vehicles were assembled in Brasov. As of April 6, 1941, the Yugoslav Air Force still had 48 Potez 25s.
Potez 25 Republican Air Force
Under the license of the English company H. G. Hawker Engineering Co. Ltd by the factories "Ikarus" in Belgrade and "Zmay" in Zemun in 1937-1938. 40 Fury fighters were assembled, which became the main Yugoslav fighters in the 30s.
Yugoslav Fury fighter
Simultaneously with the purchase of foreign aircraft, the design of our own was in progress. The first Yugoslavian aircraft proper was the training Fizir FN, which was designed in 1929 by the designer Rudolf Fizir. Serial production of the aircraft was launched at several factories of different enterprises. The prototype was flown in 1930 and almost immediately the Yugoslav Air Force placed an order for several dozen aircraft, intending to use them as close reconnaissance aircraft. The first batch of 20 aircraft powered by Walter engines was assembled at the Zmaj plant. They were followed by 10 cars with Mercedes engines, and only in 1931-1939. about 170 aircraft were produced, many of which were transferred to aviation schools. Another 20 cars were assembled in 1940. Separate copies continued to fly until the early 1950s.
Further development of the Fizir FN was a modified version of the F. P.2. The production of this aircraft began in 1934. For quite a long time, it remained the main training aircraft of the Yugoslav Air Force. 7 F. P. 2 survived until the end of the war, and were in service until complete decommissioning in 1947.
Since 1934, the Rogozarski PVT trainer has been serially built by Prva Srpska Fabrika Aeroplana Živojin Rogožarski, which is recognized for its excellent handling and excellent maneuverability. PVT aircraft were delivered to the flying schools of the military aviation of Yugoslavia in large numbers, and all Yugoslav fighter pilots were trained on them. There is no information on the number of PVTs built, but at the time of the German invasion in April 1941, the Yugoslav Air Force had 57 such aircraft. The success of the PVT attracted the attention of the Yugoslav Navy, which equipped one aircraft with light metal floats. After successful testing of this variant with a float landing gear, a series of PVT-H seaplanes (H - from Hidro) was ordered. The aircraft that survived the war were used by the Air Force of socialist Yugoslavia until the 1950s.
A further development of the PVT aircraft with a large number of metal parts in the structure and generally improved contours was the Rogozarski P-100 aircraft, which retained the same Gnome-Rhone K7 Titan Major engine; the stabilizer was redesigned and a wheel was installed in place of the tail crutch. By 1941, 27 copies were used to improve flight skills and aerobatics training. The wingspan was reduced compared to the PVT model and the top speed was increased to 251 km / h.
In 1934, the Yugoslavian company Prva Srpska Fabrika Aviona Zivojin Rogozarski built the Rogozarski SIM-X trainer. It had a circular fuselage, a parasol-type strut-braced wing and a wide-gauge fixed landing gear with separate struts. The aircraft was powered by a Walter radial engine. A significant number of these models were built. During the German invasion of Yugoslavia, about 20 aircraft were in operation at three flight schools.
At the end of the 30s, on the basis of SIM-X, the company designed a SIM-XII-H training seaplane equipped with two floats and a 190 hp Walter Major Six engine. with. (142 kW). The more powerful engine made it possible to increase the size of the aircraft. The fuselage of the SIM-XII-H had an elliptical cross-section, and the tail assembly was also reinforced.
The prototype made its first flight in February 1938, in 1939, 8 serial seaplanes were built, the last four aircraft made it possible to train pilots for instrument piloting. The remaining four aircraft were delivered without floats, as there were difficulties in their delivery from Canada. An attempt was made to develop such floats on their own, but the project could not be carried out due to the outbreak of war.
In 1936, the Yugoslav Air Force command expressed interest in a new training aircraft for training fighter pilots. For these purposes, a project was developed, which received the designation SIM-XI, which was specially equipped for performing complex aerobatics with an additional carburetor (for flying in an inverted position). Until the outbreak of World War II, mass production was never started. The only copy of the aircraft was captured by the Germans and handed over to their allies - the Croats, who used it mainly for towing gliders. On December 19, 1943, SIM-XI with tail number 7351 was shot down by partisans.
In 1931-1935, the Ikarus company created the IK-2 fighter, which became the first Yugoslav fighter of its own design. Serial production of the aircraft began in 1937, but was limited to only a pre-production batch of 12 aircraft. Powered by a Hispano-Suiza 12 Ycrs 860 hp engine. sec., IK-2 developed a maximum speed of 438 km / h and was armed with a 20 mm HS-404 cannon and two 7.92 mm Darne machine guns. The creation of this fighter was an undoubted success for the Yugoslav aviation industry.
Until 1939, new flight schools were constantly opened, where both pilots and engineers, electricians and mechanics who built and serviced aircraft were trained. When training pilots, of whom, by the way, there were not so many prepared, the emphasis was on personal aerobatic skills. Less attention was paid to tactics and actions in battle formation, since it was rightly assumed that whoever became their enemy in a real war, the numerical superiority would be on the side of the enemy, and only the personal skill of the pilots could give them a chance to win. The theoretical training of officers remained for the winter.
On September 1, 1939, World War II broke out, and the Yugoslav government decided to strengthen its air force.
Back in January 1938, Yugoslav Prime Minister Stojadinovic came to Germany with the aim of purchasing modern weapons. The military attaché of Yugoslavia in Berlin expressed his admiration for the performance of the newest German fighter, the Bf-109, and when Prime Minister Stojadinovich met with Reich Minister Hermann Goering to discuss Yugoslav military purchases, the Bf-109 was a priority on the list. Goering tried to dissuade Stojadinovich, insisting that this plane would be too complicated for the Yugoslav pilots, in fact, simply not wanting to part with the scarce fighters, but the steel, chromium and copper, with which Yugoslavia paid for the purchases badly needed by the German industry, did their case, and on April 5, 1939, a contract was signed for the supply of 50 Bf-109E aircraft and 25 DB 601 engines. The engines were delivered 11 weeks later, on June 23, and in early autumn the first 3 Bf-109E-3 fighters flew Augsburg - Zemun to join the 6th Fighter Regiment of the Air Force of the Kingdom of Yugoslavia. Additionally, an agreement was signed for the supply of 50 more Bf-109 aircraft. Some of the planes were lost in air accidents, some were transferred to flight schools. As a result, 61 Messerschmitt Bf-109E fighters entered the Yugoslav Air Force, the 2nd and 6th fighter regiments (according to other sources, 80). The Yugoslav Messerschmitts were slightly modernized, so that they weighed 40 kilograms more than their German "counterparts".
In the same year, 1938, an agreement was concluded with H. G. to replace the outdated Hawker Fury fighter. Hawker Engineering Co. Ltd on the licensed production of the Hurricane monoplane fighters, the newest for that time. In accordance with the agreement, Hawker supplied 12 Hurricanes I and authorized their production at the Rogozharsky and Zmai factories. The first of the purchased aircraft arrived on December 15, 1938. It was a fighter with a wooden propeller and wings covered with canvas. They were going to build the same in Yugoslavia. The development of production was delayed, and the Yugoslav Air Force bought 12 more aircraft in England. They already had new Merlin IV motors, variable pitch propellers and metal wing skins. By the time the Germans attacked Yugoslavia, out of 60 ordered "Zmai" had managed to produce 20, and "Rogozharsky" out of 40 - none. Thus, in the ranks of the Yugoslav Air Force on April 6, there were 38 Hurricanes, which were in service with the 51st, 33rd and 34th squadrons. In Yugoslavia, one Hurricane was converted to a German DB601A engine. This machine has been tested since the beginning of 1941 and, according to the pilots' reviews, exceeded the standard ones; her further fate is unknown.
In turn, the Yugoslav designers offered their own fighter, the Ikarus IK-3. The Yugoslav fighter turned out to be so reliable and easy to fly that it surpassed its outstanding contemporaries in this: the British Hawker Hurricane and the German Messerschmitt 109. The aircraft was equipped with a French Hispano-Suiza 12Y-29 engine with a capacity of 890 hp, which allowed a speed of 526 km / h Armed with a 20mm Oerlikon FF / SMK M.39 E. M.cannon firing through the propeller hub and two 7.92mm Browning FN machine guns under the hood in the upper front fuselage. The aircraft was equipped with the German Telefunken Fug VII radio station. Unfortunately, only 13 of these machines were produced, of which 12 had entered combat units by April 1941.
It was decided to strengthen the bomber aviation.
In 1936-1937, Yugoslavia purchased the 37 Do 17 K - an export version of the German Dornier Do.17 bomber with French 14-cylinder radial twin-row air-cooled engines Gnome-Rhone 14N1 / 2, with a capacity of 980 hp each. At the same time, the Yugoslav government was negotiating with the Dornier firm to purchase a license to manufacture Do 17, and on May 15, 1939, assembly lines of state aircraft factories in Kraljevo began production of Yugoslav Do 17Ks. Until April 1941, when the German invasion of Yugoslavia began, only 30 Do 17Ks were fully assembled. All Yugoslav Do 17 K, in contrast to the serial German Do 17, had an elongated nose. The Do 17 K bombers entered service with the 3rd Air Regiment of the Royal Yugoslav Air Force in 1939.
Two British Bristol BLENHEIM Mk I bombers delivered to Yugoslavia became the benchmark for 48 Blenheims built under license by the Ikarus factory in Belgrade. These machines, along with 22 more modern Blenheim IVs that arrived from Great Britain in early 1940, were in service with the 8th Bomber Regiment and the 11th Separate Group of the Yugoslav Air Force.
Despite the fact that Italy was an enemy of Yugoslavia, supporting the Croatian Ustasha, combat aircraft were also purchased from it. In mid-1938, an agreement was signed for the sale of 45 Savoia Marchetti S. M. medium bombers. 79 to Yugoslavia. All of them were of the standard Italian model without any peculiarities, and the delivery was carried out swiftly - they simply redirected thirty S.79s, sent to one of the regiments of the Italian Air Force, and delivered 15 new ones - from the factory. In Yugoslavia, they armed one regiment (7th - 30 vehicles) and 81st separate bomber group (15 vehicles).
12 Caproni Ca.310 LIBECCIO light reconnaissance bombers were also purchased.
Yugoslav designers tried to create their own bombers. One of them was Ikarus ORKAN, first demonstrated in 1938 at the First International Aviation Exhibition in Belgrade. The Orcan was an all-metal monoplane with a duralumin working skin. The project was calculated for 14-cylinder Hispano-Suiza 14AB (670 hp) engines, of a relatively small diameter. But after France entered the war, the supply of engines from this country stopped, then the Air Force leadership agreed to test a car with Italian 840-horsepower Fiat A-74RC-38 engines of greater power, but at the same time of a larger diameter. Italian variable pitch propellers were installed. The prototype, while unarmed, took off for the first time on June 24, 1940. During landing, the plane was damaged, it was repaired for a long time; there was a particularly shortage of French spare parts. Only on March 19, 1941 it was possible to continue testing. There was not enough time to fine-tune the aircraft. The Orkan prototype was damaged during a raid by German aircraft, captured by the Germans as a trophy and taken by train to Germany, where its traces are lost.
In 1923, the seaplane was allocated and reassigned to the command of the Naval Forces. In the same year the company "Ikarus" began to build flying boats in its workshops (Novi Sad). The first was the Ikarus SM two-seater biplane flying boat powered by a 100 hp Mercedes D. II engine. with. … In subsequent series, the boat was equipped with Czech Blesk engines with a capacity of 100 hp. and German Mercedes D. II with 120 and 160 hp. The first flight of the flying boat took place on November 10, 1924. The SM boat was produced in a limited edition for the Royal Yugoslav Navy. A total of 42 copies of the boat were produced. These unpretentious and comfortable machines were used for 18 years, until April 1941.
The next flying boat, Ikarus IM, did not go into production. But on its basis, an improved version of Ikarus IO was created. It was a biplane with uneven wingspan, but with a 400 hp Librerti L-12 engine. and the same crew accommodation. In 1927, the first series of 12 vehicles was built for the reconnaissance purposes of the fleet. Flying boat IO was armed with one 7.7 mm machine gun on a ring mount in the bow of the hull. A total of 38 copies of four types were produced - IO / Li with a Librerti L-12 400 hp engine (36 + 1 prototypes were built in 1927 and 1928), IO / Lo - with a Lorraine-Dietrich 12Eb 450 hp engine.., (1 prototype in 1929), IO / Re - with Renault 12Ke 500 hp engine. (1 prototype in 1937) and IO / Lo with 400 hp Lorraine Dietrich-12dB engine. (20 copies in 1934).
In addition to its own aircraft, the naval aviation of Yugoslavia was also equipped with foreign models - reconnaissance torpedo bombers Dornier Do 22. In total, from 1938 to 1939, 12 aircraft were delivered under the designation Do.22Kj.
In 1940, the reconnaissance seaplane and light bomber Rogozarski SIM. XIV, a twin-engine monoplane with two floats, entered service. The prototype SIM-XIVH made its first flight on February 8, 1938. It was the first Yugoslav twin-engine military aircraft of the Yugoslav design. Serial production was launched at the beginning of 1940 at the Rogozharsky plant in Belgrade with final assembly at the naval aviation workshops. A total of 13 copies were issued.
By 1941, the Yugoslav Royal Air Force had 1,875 officers and 29,527 privates, as well as more than 460 front-line aircraft, most of which were of modern types. The Air Force had 22 bomber and 19 fighter squadrons.
From old Breguet Br.19 and Potez 25 aircraft, 7 reconnaissance groups of 2 squadrons were formed, 1 group for the army of ground forces. For the needs of the high command, two separate reconnaissance groups were formed. Also, 2 new fighter regiments were formed, armed with German Messerschmitt Bf.109 fighters and British Hawker Hurricane fighters. The 4th Bomber Brigade was formed from the 1st and 7th Bomber Regiments, and the 81st Bomber Group was sent from the 1st Brigade to Mostar.
From transport, light, medical aircraft and communications aircraft, auxiliary air forces began to be formed, but by the beginning of the war this was not completed. The Air Force Academy was founded in Pancevo in 1940.
The organization of the air defense of cities, garrisons and roads was completed at the beginning of 1940. Only the troops were provided with air defense systems. The weapons were modern, but they weren't enough. The Air Force command had 2 air defense battalions armed with 75 mm M-37 guns, and each army had an air defense battalion equipped with 75 mm M-37 or 76 guns, 5 mm M-36 guns and a group of searchlights. Each division had a machine gun company with 6 15 mm M-38 machine guns (Czechoslovak ZB-60).
The Yugoslavs expected either to prevent the invasion of the country or to delay the Luftwaffe until the Allies approached. Time has shown how futile these expectations were …
