Avia BH-33

Infobox Aircraft
name=BH-33


caption=
type= Fighter
manufacturer=Avia, PWS (under licence), Ikarus (under licence)
designer=
first flight= 21 October, 1927
introduced=
retired=
status=
primary user= Czechoslovak Air Force
more users= Polish Air Force Yugoslav Royal Air Force
produced=ca. 110, plus 50 licence-built in Poland and 22 in Yugoslavia
number built=
developed from = Avia BH-21
variants with their own articles= PWS-A

The Avia BH-33 was a biplane fighter aircraft built in Czechoslovakia in 1927. It was based on the BH-21J that demonstrated promising results by marrying 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).

Design and development

Initial tests of the first prototype were disappointing, displaying performance only marginally better than the BH-21, even when fitted with a more powerful version of the Jupiter. Two further prototypes followed, both designated BH-33-1, each with an increasingly powerful Jupiter variant - one a Jupiter VI, the other a Jupiter VII. The performance of the latter example was finally good enough for the Czechoslovakian war ministry to order a small production run - of only five aircraft. Three examples were sold to Belgium, where there were plans to build the type under licence, but this did not eventuate. Licence production was undertaken, however, in Poland, where a single example was sold along with a licence to build fifty aircraft. These were designated PWS-A and put into service with the Polish Air Force in 1930 [Belcarz, "Avia BH-33 (PWS-A), PWS-10, PZL P.7a", p.6] .

Development continued with an almost total redesign of the fuselage, replacing the wooden, slab-sided structure with one of oval cross-section built up from welded steel tubes. Designated BH-33E, this was at last a world-class fighter for its time. Nevertheless, the response from the Czechoslovakian military was lukewarm (although two were bought for the national aerobatics team), and Avia again looked abroad for customers, this time selling twenty aircraft to Yugoslavia, along with a licence to produce another twenty-four. Two or three examples were also bought by Russia for evaluation.

In late 1929, a further development was flown as the BH-33L, featuring longer-span wings, and a Škoda L W-block engine. This version finally brought the company the domestic sales that it had been hoping for, with eighty aircraft ordered by the air force. These became standard equipment with some air regiments up to the outbreak of World War II.

A single, final variant with a BMW-built Pratt & Whitney Hornet engine was built as the BH-33H (later redesignation BH-133) in 1930, but this did not lead to production.

Operational history

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 Bf 109s, but were both destroyed and their pilots killed.

Variants

;BH-33:First prototype.;;BH-33-1::Two prototypes powered by Jupiter VI (second) and Jupiter VII (third) engines plus 5 serial built aircraft with Jupiter VII engine.;BH-33E:Rebuilt fuselage;BH-33L:Version with longer span wings and powered by Škoda L engine, 80 built.;BH-33H (BH-133):Version powered by Pratt & Whitney Hornet engine, 1 built.;PWS-A:Polish license-built variant of the BH-33 with minor modifications [Belcarz, "Avia BH-33 (PWS-A), PWS-10, PZL P.7a", p.6] , 50 built between 1929 and 1932.

Operators

;BEL
*Belgian Air Force received 3 BH-33-1 aircraft.;CZS
*Czechoslovakian Air Force;POL
*Polish Air Force received 1 BH-33 and 50 PWS-A license-built variant.;USSR
*Soviet Air Force bought 2-3 BH-33E for tests.;flag|Yugoslavia|kingdom
*Yugoslav Royal Air Force

pecifications (BH-33L)

aerospecs
met or eng?= met

crew=one pilot
capacity=
length m=7.22
length ft=23
length in=8
span m=8.90
span ft=29
span in=2
dia m=
dia ft=
dia in=
height m=3.13
height ft=10
height in=3
wing area sqm=25.5
wing area sqft=274
rot area sqm=
rot area sqft=
aspect ratio=
empty weight kg=1,117
empty weight lb=2,463
gross weight kg=1,560
gross weight lb=3,439

eng1 number=1
eng1 type=Škoda L
eng1 kw= 430
eng1 hp= 580
eng1 kn=
eng1 lbf=
eng1 kn-ab=
eng1 lbf-ab=
eng2 number=
eng2 type=
eng2 kw=
eng2 hp=
eng2 kn=
eng2 lbf=
eng2 kn-ab=
eng2 lbf-ab=

max speed kmh=298
max speed mph=186
max speed mach=
cruise speed kmh=
cruise speed mph=
range km=280
range miles=450
endurance h=
endurance min=
ceiling m=8,000
ceiling ft=26,200
glide ratio=
climb rate ms=9.9
climb rate ftmin=1,940
sink rate ms=
sink rate ftmin=

armament1=2 × fixed, forward-firing .303 Vickers machine guns
armament2=
armament3=
armament4=
armament5=
armament6=

References

*
*
* Belcarz, Bartłomiej (2005). "Avia BH-33 (PWS-A), PWS-10, PZL P.7a", Polskie Skrzydła #3. Sandomierz: Wydawnictwo Stratus, ISBN 83-89450-36-4 (Polish language).
* Němeček, Vaclav (1968). "Československá letadla". Praha: Naše Vojsko.
* [http://www.airwar.ru/enc/fww1/bh33.html airwar.ru]

ee also

aircontent

related=
BH-17 -
BH-21 -
BH-22 -
BH-23

similar aircraft=

sequence=
BH-27 -
BH-28 -
BH-29 -BH-33

lists=

see also=