Avia B-534 and Avia Bk-534

Avia B-534 (fourth version) of 42nd letka.

Avia B-534

The prototype of B-534 flew for the first time on 25 May 1933. An imported French-produced Hispano-Suiza HS-12Ybrs engine powered it; not an intended HS-12Ydrs, which was to be used in the series-production, license manufactured in Czechoslovakia.
It was first displayed for the public on 10 September 1933 at Army air day, five days after the first flight of the second prototype.
The first procurement order for the B-534 was issued from the Ministry of National Defence to the Avia Company on 17 July 1934 and was for 147 aircraft’s. The first machines were delivered to the Air Force in autumn of 1935.
The Ministry of National Defence ordered the next, second procurement batch of 46 B-534’s in 1936. The first 26 belonged to version 3 and were received by the units in March and April 1937.

Avias B-534 of two different versions. A fourth version aircraft with a third version aircraft in the background.

Before the end of 1936 the Ministry of National Defence awarded the third, largest order for the B-534. The contract was originally for 134 aircraft (s/n B-534.194 to B-534.327), but owing to the growing German menace it was increased by the fourth contract for further 50 machines (s/n B-534.328 to B-534.377). The last, fifth procurement order, placed in August 1938 was for 68 machines (s/n B-534.378 to B-534.445).
The number of Avia B-534’s produced for the Czechoslovak Air Force, thus reached 445.

Version 1 of the Avia B-534 included s/n B-534.2 to B-534.101.
Version 2 of the Avia B-534 included s/n B-534.102 to B-534.147.
Version 3 of the Avia B-534 included s/n B-534.148 to B-534.173.
Version 4 of the Avia B-534 included s/n B-534.174 to B.534.445.

A flight of Avias B-534 (first version) of 31th letka.

Technical details B-534 version 4
Span:____________9.4 m
Lenght:__________8.1 m
Engine:__________Avia built Hispano-Suiza 12Ydrs / 830 hsp.
Max speed:_______380 km/h
Service ceiling:_10500 m
Range:___________600 km
Armament:________4x7.92 mm Mk.30 machine guns

Avia B-534 (fourth version) on skies.
Image kindly via Johan Löfling.

Avia Bk-534

The Avia Bk-534 was to be a cannon armed version of the B-534 with a license manufactured Hispano-Suiza HS-12Ycrs with the cannon barrel through the hollow airscrew reduction gear shaft.
In 1937, fifty of the Bk-534 was ordered, with a supplemental order for further four machines issued shortly afterwards (s/n Bk-534.501 to Bk-534.554). Further 66 (s/n Bk-534.555 to Bk-534.620) were ordered shortly before the Munich crisis.
Teething troubles with the cannon armament were not solved by the time the production of the first batch was begun in late summer 1938 and so a third 7.92mm machine gun was installed instead. The same was repeated when production of the second batch was started early in 1939. As a result, the Bk-534 was the weaker-armed instead of being the more powerfully armed variety of the original fighter.
More Avia Bk-534’s were made for the Nazi Luftwaffe than for the Czechoslovak Air Force. With the exception of the three first machines, the Bk-534’s from the second batch procured were taken over by the German occupants.

Avia Bk-534 included s/n B-534.501 to B-534.620.

Avias B-534 (fourth version) at the Avia factory airfield in Prague-Cakovice.

Technical details Bk-534
Span:____________9.4 m
Lenght:__________8.2 m
Engine:__________Avia built Hispano-Suiza 12Ycrs / 830 hsp.
Max speed:_______375 km/h
Service ceiling:_9500 m
Range:___________500 km
Armament:________3x7.92 mm Mk.30 machine guns

Known claims with the Avia B-534 and Avia Bk-534

Slovak Air Arm use of the Avia B-534 and Bk-534 during the Second World War
The Slovak National Uprising
Bulgarian Air Force use of the Avia B-534 during the Second World War
Luftwaffe use of the Avia B-534 and Bk-534 during the Second World War
Greek Air Force use of the Avia B-534 during the Second World War
Soviet Air Force use of the Avia B-534 during the Second World War
Hungarian Air Force use of the Avia B-534 during the Second World War

Avia B-534 - Jirí Vraný, 1994 MBI, Praha, ISBN 80-901263-6-7