During the course of 1926, Avia tested the Gnome-Rhone version of the Bristol Jupiter nine-cylinder radial air-cooled engine in a BH-21 airframe, and elected to employ this power plant for a new fighter, the BH-33. This, the last fighter design to be produced by Benes and Hajn for the Avia concern, was the first Avia fighter to feature a fixed tail fin from the outset, and commenced flight trials in 1927.
The wood-framed wings and fin were partly covered by plywood and wholly by fabric. A steel-framed fuselage, rudder and elevator were covered by fabric. Sheet metal plated cowling.
Avia Ba-33 of No 1 Fighter Regiment
It was ordered into production for the Czechoslovak air arm with a Walter-built Jupiter VI rated at 543hp for take-off, armament comprising two 7.7mm machine guns.
A manufacturing licence for the BH-33 was acquired by Poland in 1928, PZL building 10 pre-production fighters of this type and PWS building some 50 production examples for the Polish Air Force as the PWS A from 1930. Three BH-33s were supplied to Belgium in 1929.
Avia Ba-33 of No 1 Air Regiment at Cheb
Engine: Walter Jupiter Mk VI, 450 hp
Propeller: two blade wooden
Wingspan: 8.90 m / 29 ft 2 in
Length: 7.04 m / 23 ft 1 in
Wing area: 22.20 sq.m / 238.96 sq ft
Max take-off weight: 1253 kg / 2762 lb
Empty weight: 830 kg / 1830 lb
Max. speed: 285 km/h / 177 mph
Rate of climb: 10.5 m/s
Range: 450 km
Armament: 2 x synchronized 7.7mm