Avia BH-21

__NOTOC__ Infobox Aircraft
name=BH-21


caption=
type=Fighter
manufacturer=Avia
designer=Pavel Beneš and Miroslav Hajn
first flight=January 1925
introduced=
retired=
status=
primary user=
more users=
produced=
number built=126 + 50 licence-built in Belgium
variants with their own articles=

The Avia BH-21, first built in 1925, was a robust biplane that served an important role in securing Czechoslovak national security during the period between the Great War and the Second World War. As well as being a competent fighter, it was also an accomplished racer, winning several air races of its time.

History

A conventional biplane, the predecessor of the BH-21, the BH-17, was designed by Pavel Beneš and Miroslav Hajn in 1922 as a response to a Czechoslovak Defense Department requirement for a new fighter aircraft. The BH-17 was actually only part of five Avia designs submitted to the Defense Department along with competing designs from the Letov Kbely and Aero companies. After extensive review, the BH-17, one of Avia's three biplane designs, was chosen and limited production initiated for evaluative purposes. Testing revealed some deficiencies in the BH-17 and a subsequent redesign in 1924 morphed the BH-17 into its final form as the BH-21 which included straightened interplane bracing and allowed for better field of view for the pilot. A special training version, designated the BH-22, was also created. Both versions utilized convert|180|hp|abbr=on Hispano-Suiza 8fb engines built under license by Škoda. The BH-21 was put into production in 1925 and had a one-year production run which yielded 170 aircraft with 126 being produced by Avia for the Czechoslovak Air Force while another 50 were produced under license by the Belgian company, "Société Anonyme Belge de Constructions Aéronautiques" "SABCA" for the Belgian Air Force. While in service the BH-21 saw no combat as it was retired before the outbreak of World War II. In spite of this it served as an important stepping stone to the more advanced BH-33 and BH-53 types. The BH-21's most lasting achievement came when a racing version, the BH-21R, won several national air-race competitions in 1925 sporting an upgraded HS 8Fb engine producing over convert|400|hp|abbr=on.

Variants

* BH-21 : Single-seat fighter aircraft.
* BH-21J : One BH-21 fitted with a Bristol Jupiter radial piston engine. Led to the development of the Avia BH-19.
* Bh-21R : Single-seat clipped-wing racing aircraft.

Operators

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pecifications (BH-21)

aircraft specifications
plane or copter?=plane
jet or prop?=prop
ref=
crew=one, pilot
capacity=
payload main=
payload alt=
length main= 22 ft 6½ in
length alt= 6.87 m
span main= 29 ft 2 in
span alt= 8.90 m
height main= 8 ft 11 in
height alt= 2.74 m
area main= 236 sq.ft.
area alt= 21.96 sq.metres
airfoil=
empty weight main= 1,587 lb
empty weight alt= 720 kg
loaded weight main=
loaded weight alt=
useful load main=
useful load alt=
max takeoff weight main= 2,392 lb
max takeoff weight alt= 1,085 kg
more general=
engine (prop)= Hispano-Suiza 8Fb
type of prop=V8 engine
number of props=1
power main= 305 hp @ 1850 rpm
power alt= 228 kW
power original=
max speed main=132 knots at 9,800 ft (3,000 m)
max speed alt= 152 mph / 245 km/h
cruise speed main=
cruise speed alt=
stall speed main=
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main=
range alt=
ceiling main= 18,050 ft
ceiling alt= 5,500 m
climb rate main= 16 minutes to convert|16400|ft|m|abbr=on
climb rate alt= 16 minutes to 5000 m
loading main=
loading alt=
thrust/weight=
power/mass main=
power/mass alt=
more performance=
* Endurance: 2 h 0 min
armament=
* 2 × .303 in Vickers machine guns in the upper front fuselage
avionics=

ee also

aircontent
related=
BH-17 -
BH-22 -
BH-23 -
BH-33
similar aircraft=
sequence=
BH-17 -
BH-19 -
BH-20 -BH-21 -
BH-22 -
BH-23 -
BH-25
lists=
see also=