During 1932, the Czechoslovak aircraft company Avia flew the first prototype of a single-engined fighter biplane, the Avia B-34, designed by aeronautical engineer 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 450 kilowatts (600 hp) 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.
The prototype was sent for testing in September and was redesignated 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 by having an enclosed cockpit, and a revised tail and undercarriage.
On 14 April 1934, the second prototype, while flown by test pilot Václav Kočí, successfully attained a Czechoslovak national speed record of 365.7 kilometres per hour (227.2 mph).
During 1932, the Czechoslovak aircraft company Avia flew the first prototype of a single-engined fighter biplane, the Avia B-34, designed by aeronautical engineer 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 450 kilowatts (600 hp) 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. The prototype was sent for testing in September and was redesignated 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 by having an enclosed cockpit, and a revised tail and undercarriage. On 14 April 1934, the second prototype, while flown by test pilot Václav Kočí, successfully attained a Czechoslovak national speed record of 365.7 kilometres per hour (227.2 mph).
Avia B-534