The Last of the Old Guard
Though the interwar period is generally considered the time when the biplane gave way to the monoplane, the transition from one to the other was a gradual one in many contexts.
Biplanes were not without their merits and several military air arms around the world kept biplanes as their primary fighter aircraft through much of the interwar era. Compared to monoplane fighter designs of the time, biplane fighters often offered superior performance with regards to climbing, maneuverability and general responsiveness.
The Avia B.534 became symbolic of Czechoslovak air power of the time and , along with the Fiat CR.42 Falco from Italy and the Polikarpov I-153 Chaika from the Soviet union, widely considered to represent the apex of biplane fighter development. All three types were still active in the fighter role during the early stages of the Second World War; in fact, the last confirmed aerial combat victory for a biplane fighter was scored in an Avia B.534.
The Man Behind the Machine
The designer of the B.534, František Novotný, came into employment as Avia’s chief engineer in 1930 after the company’s founders left it after it merged with the Škoda company.
Novotný, a First World War veteran, had a deep interest in aviation from a young age and spent a brief time in Great Britain working for H.G.Hawker before returning to his native Czechoslovakia to complete his education as an engineer. Much of what he learned about aircraft design and engineering during his time at Hawker benefited Avia greatly as he applied that knowledge to aircraft he designed and oversaw the production of.
The B.534 had its starting point in the B.34, the first aircraft Novotný designed after coming to Avia. In 1932, the company secured a modern French built Hispano-Suiza 12 cylinder in-line engine and installed it to the second B.34 prototype. With much modification and streamlining, this arrangement served as the prototype B.534 and took to the air for the first time in May of 1933.
The B.534 entered service with the Czechoslovak military in late 1935. The aircraft was of very clean design and a combination of metal, fabric and wood construction. While the initial version of the type suffered some structural problems in service; it was a fast and responsive machine that was popular with pilots that would quickly, through four variations, mature into a very competent and dependable fighter aircraft for its time.
Before the 1930s were finished, the B.534 had shown itself to be a very close match for Germany’s Messerschmitt Bf-109B fighter in speed. In an international competition in Switzerland in 1937, the Avia biplane was clocked at only 11 kilometers per hour slower than the German monoplane fighter.
Into the Fray
The Munich Agreement of 1938 saw Czechoslovakia come under Hitler’s boot heel and, consequently, the country’s military assets annexed by Germany. In 1939, when Germany forcibly split the country into the Bohemian and Moravian Protectorate in the west and the Slovak Republic in the east, the B-534 got its first taste of combat.
Almost as soon as the Slovak Republic had been established under a Nazi friendly collaborationist government, Hungarian forces staged an attack on Slovak territory. In a series of skirmishes along the border of the two countries; Slovak Avias secured no aerial victories and a number were lost to anti aircraft fire and Hungarian fighters.
It was in this initial combat that the B.534’s weaknesses became apparent; it was lightly armored, lacked self sealing fuel tanks and also lacked guns of sufficient calibre. While these weaknesses would not keep it from seeing further combat, they would ensure the aircraft would be a bit player at most in the Second World War.
Through the first year or so of the war, Slovakia also used the aircraft along the Eastern Front in small actions against Poland and the Soviet Union.
The last action for Slovak Avias occurred in 1944 as part of the Slovak National Uprising, a resistance movement aimed at toppling the collaborationist power structure and turning against Germany. By this point, the B.534 was thoroughly outclassed as a fighter. Nevertheless, in early September of that year, a B.534 flying under resistance colours shot down a Hungarian Junkers Ju-52 transport bound for Poland. While this action was the last confirmed aerial victory for a biplane fighter, it would have been preferable if the transport had been forced down to be kept in usable condition as the resistance was desperate for any aircraft it could get. Ultimately, the resistance movement was stopped.
Aside of Slovakia, the only other nation to field the B.534 as a fighter in the war was Bulgaria. The Bulgarians purchased several Avias from Germany and notably used some of them against American bombers which raided the oilfields of Ploiesti, Romania in August of 1943. Though the Avias did score hits against the bombers, their guns were not powerful enough to penetrate the American aircrafts’ armor.
The German Luftwaffe used the many Avias it confiscated from Czechoslovakia as trainers and glider tugs.
Minor users of the B.534 included: Croatia, Greece, Hungary, Romania and the Soviet union.
The B.534 Family
The basic B.534 evolved across four sub types, referred to as series. Most of the differences that set the four series apart from each other were quite subtle and involved internal structural strengthening, rearrangement of gun installations and general streamlining of the design.
The ultimate development of the basic design was the Series IV aircraft. A notable difference between the Series IV Avia and earlier ones was a completely enclosed cockpit that included a heater for pilot comfort.
Most B.534 aircraft were equipped with wooden propellers, though many later Series IV aircraft were fitted with more modern metal ones.
While the Avia had aerodynamic fairings placed over its wheels as standard equipment; in practice, these fairings were often removed as they tended to clog with mud when the aircraft operated from wet grass airstrips. The Avia also had the ability to be fitted with skis for operations from snow.
The specialized Bk.534 was designed to have a 20mm cannon firing though the propeller hub via a hollow shaft. Two of the aircraft’s standard four machine guns were removed to offset the weight of the larger cannon. However, adapting the cannon to the design proved problematic and it ultimately never came into use with the aircraft.
A notable chapter to the Bk.534 story took place when the German navy modified three of them to test the type for suitability for aircraft carrier operations. While they were found to be completely unsuitable; it was of little consequence as the German aircraft carrier, Graf Zeppelin, never was built.
Lastly, the B.634 of 1936 was an attempt to refine the aerodynamics and performance of the B.534 further. While gains in performance were achieved, the B.634 had a number of problems which eventually led to only one ever being built.
What Remains and Learning More
The B.534 could be considered a ghost in the truest sense of the word as none of the roughly 560 built have survived to the present day. All we have are images of what once was.
Two full scale replicas built from original plans are on display in museums in Prague, Czech Republic and Košice, Slovakia.
Additionally, since 2013, a 30% scale replica of a Series IV aircraft has been flying on the Czech civil register. Though the replica is smaller than the original, great care has been taken to ensure it faithfully echoes the shape and proportions of the real thing.