Avia B-534

The Avia B-534 is a Czechoslovak biplane produced during the period between the Great War and World War II.


Avia B-534
Class Aircraft
Type Fighter
Manufacturer Avia
Origin Czechoslovakia
Country Name Origin Year
Czechoslovakia 1933
Country Name Operational Year Retirement Year
Bulgaria 1935 View
Croatia 1935 View
Czechoslovakia 1935 View
Germany 1935 View
Greece 1935 View
Hungary 1935 View
Romania 1935 View
Russia (USSR) 1935 View
Slovakia 1935 View
ManufacturerName Production From Production To Quantity
Avia 665 View

In 1932, the Czechoslovak aircraft company flew a first prototype of a single-engined fighter biplane, the Avia B-34, designed by František Novotný. After modification, the Czechoslovak Ministry of Defence placed an order for B-34s. A second prototype, the Avia B-34/2, was built, which was intended to be powered by a 600 horsepower (450 kW) Avia Rr 29 radial engine instead of the Hispano-Suiza 12N V12 engine of the first prototype and the initial production series. This engine proved prone to overheating and vibration, however, and it was decided to re-engine the B.34/2 before it flew, fitting it with a Hispano-Suiza 12Ybrs V12 engine.

The Avia B-34/2 made its maiden flight on 25 May 1933.[citation needed] The prototype was sent for testing in September and was redesignated as B-534.1. On 10 September, the B-534 was displayed to the public for the first time at an Army Air Day. It was to compete against the Praga E-44 and Letov Š-231.

A second prototype, the B-534/2 was completed in September 1933. It differed from the first prototype in having an enclosed cockpit, a revised tail and undercarriage. On 14 April 1934 test pilot Václav Kocí successfully gained a Czechoslovak national speed record of 365.7 kilometres per hour (227.2 mph).

More testing followed and an initial order for 34 aircraft for the Czechoslovak Air Force, soon increasing to 147, was placed on 17 July 1934. At that time, the B-534 was well ahead of its contemporaries. The United Kingdom was still dependent on Hawker Furies, with the first Gloster Gladiators being produced at this time. The Soviet Union was placing its hope on its Polikarpov aircraft designs. The United States was still using descendants of the Curtiss Hawk series, with the Seversky P-35 and Curtiss P-36 just about to fly as prototypes.

The B-534 was designed as a single-engine biplane fighter with a license-built Hispano-Suiza inline powerplant, and fixed landing gear. The air forces of the 1930s were reluctant to abandon the maneuverability and climb rates of biplanes for the speed of monoplanes, even in the face of new and better technology. The success of the Soviet pilots with biplanes may have contributed to this reluctance; they were known to strip their aircraft of sliding canopies, preferring to have the wind in their faces. Aircraft with two fabric-covered wings and fixed landing gear were also less expensive to manufacture.

First deliveries of the B-534 to the Czechoslovak air force began in October 1935, and 666 or so had been completed by 1938. The first 100 of these were of the first series. The second prototype was the blueprint for the I series, although it was built with an open cockpit. These early series aircraft were initially armed with four 7.92mm vz.28 guns. Two were located in the nose either side of the engine in a similar manner to the Avia B-34 and two were fitted in the wings. At an early stage of production it was however recognised that the wing mounted guns were troublesome. Aircraft from serial number B-534.47 were completed without the wing guns, which were also removed from the earlier aircraft. The first to fourth series aircraft were fitted with the Avia licence built version of the Hispano-Suiza 12Ydrs engine. This was a liquid cooled V12 cylinder engine with a capacity of 36.05 litres. On the ground its normal power rating was 650 hp, it could deliver 750 hp for two minutes. At an operational height of 4,000 m (13,123 ft), it could reach 860 hp. Total fuel was 347 litres (76 gal) which was held in two fuselage fuel tanks of 90 and 257 litres.

The II series completed the remainder of the first order from the Czechoslovak Government, These were forty-five aircraft numbered B-534.102 to 147. Like the I series these carried four guns. However the solution to the problems with the wing mounted guns was to move these guns, now upgraded to the vz.30 to the fuselage with the others. The four 7.92 mm (0.312 in) machine guns were located in the sides of the fuselage, firing through the propeller. One very modern innovation was a bubble canopy. This was tested on a small number of the early series aircraft, although certainly not a standard fit.

Variants

  • B-534/1: First prototype.
  • B-534/2: Second prototype.
  • B-534-I: First production version.
  • B-534-II:
  • B-534-III:
  • B-534-IV: Closed canopy
  • Bk-534: Cannon version

On 1 September 1938, less than a month before the Munich Agreement would cause Czechoslovakia to lose 30% of its territory and 34% of its population, 328 B-534 and Bk-534s equipped 21 fighter squadrons of the Czechoslovak Air Force, with other aircraft being assigned to reserve and training squadrons, and deliveries continuing of the final batch of fighters. On 14 March 1939, Germany forced the partition of Czechoslovakia, with Slovakia being declared as the nominally independent Slovak Republic with Germany annexing the remaining "Czech" part of Czechoslovakia as the Protectorate of Bohemia and Moravia the next day. The Slovenské vzdušné zbrane (Slovak Air Force) was organised out of the units of the Czechoslovak Air Force that were based in Slovakia at the time of partition, and inherited about 71 B-534s and Bk-534s.

Slovakia quickly had to use its new formed air force, weakened by the departure of Czech pilots, to defend itself when Hungary invaded on 23 March 1939. Two B-534s were shot down by Hungarian anti-aircraft fire with four more being shot down by Hungarian Fiat CR-32 fighters and another Avia making a forced landing behind Hungarian lines, and being captured.

In September 1939, Slovakia participated in the German Invasion of Poland, with the aim of regaining territories lost to Poland at Munich. Two squadrons of B-534s supported the attack, escorting Luftwaffe Junkers Ju 87 bombers on eight missions, losing two B-534s while claiming a single Polish RWD-8 liaison aircraft shot down.

Role Fighter aircraft
Manufacturer Avia
Designer František Novotný
First flight 25 May 1933
Introduction 1935
Status Retired
Primary user Czechoslovak Air Force
Number built 665


General characteristics

  • Crew: 1
  • Length: 8.2 m (26 ft 11 in)
  • Wingspan: 9.4 m (30 ft 10 in)
  • Height: 3.1 m (10 ft 2 in)
  • Wing area: 23.56 m2 (253.6 sq ft)
  • Empty weight: 1,460 kg (3,219 lb)
  • Gross weight: 1,985 kg (4,376 lb)
  • Max takeoff weight: 2,120 kg (4,674 lb)
  • Powerplant: 1 × Hispano-Suiza 12Ydrs liquid-cooled V12 engine, 634 kW (850 hp)

Performance

  • Maximum speed: 405 km/h (252 mph; 219 kn) at 4,400 m (14,436 ft)
  • Cruising speed: 345 km/h (214 mph; 186 kn)
  • Range: 580 km (360 mi; 313 nmi)
  • Service ceiling: 10,600 m (34,777 ft)
  • Rate of climb: 15.1 m/s (2,970 ft/min)
  • Time to altitude: 5,000 m (16,404 ft) in 4 minutes 28 seconds
  • Wing loading: 90.2 kg/m2 (18.5 lb/sq ft)
  • Power/mass: 0.292 kW/kg (0.178 hp/lb)

Armament

  • Guns: 4× 7.92 mm (0.312 in) vz. 30 (Ceská zbrojovka Strakonice) machine guns with 250-300 rpg
  • Bombs: 6× 10 kg (22 lb) or 4x 20 kg (44 lb) bombs

End notes