The Avia BH-33 was a biplane fighter aircraft built in Czechoslovakia in 1927.
It was based on the BH-21J which demonstrated promising results by combining the original BH-21 airframe with a licence-built Bristol Jupiter radial engine.
Other than the peculiar Avia hallmark of having an upper wing with a shorter span than the lower, it was utterly conventional, even featuring a tail fin for the first time in a Pavel Beneš and Miroslav Hajn design (previous aircraft had a rudder but no fin).
Czechoslovakian BH-33s never saw combat, and Poland’s examples had long been replaced in service by the time of the German invasion.
Two Yugoslavian machines did, however see combat against Luftwaffe Messerschmitt Bf 109s, but were both destroyed and their pilots killed.
BH-33, First prototype.
BH-33-1, Two prototypes powered by Jupiter VI (second) and Jupiter VII (third) engines plus five serial built aircraft with Jupiter VII engine.
BH-33E, Rebuilt fuselage
BH-33E-SHS, Yugoslav Version powered by IAM K9 engine, 22 built.
BH-33L, Version with longer-span wings, powered by a Škoda L engine, 80 built.
BH-33H (BH-133), Version powered by Pratt & Whitney Hornet engine, one built.
P.W.S.A, Polish license-built variant of the BH-33 with minor modifications, 50 built between 1929 and 1932.