The Avia B.534 was the
most important Czech aircraft of the period between the two world wars,
with production totalling 566, more than that of any other type. It was
a classic single-seat fighter biplane, representing the penultimate
stage in the evolution of this type. The final stage being provided by
biplanes with retractable landing gear, such as the Soviet Polikarpov
1-153 and the Grumman fighters for the US Navy.
Novotny had re-engined the unsuccessful Avia B.34/2 prototype with a
Hispano-Suiza 12Ybrs engine, redesignating it B.534/1. It first flew in
August 1933, piloted by Vaclav Koci, and showed great promise. The
aircraft was an unequal-span staggered single-bay biplane, with splayed
N-struts carrying the upper-wing centre section above the fuselage.
Wing bracing was by N-struts and there were ailerons on both upper and
lower wings. The two-spar riveted steel wing had fabric covering, while
the carefully streamlined fuselage was a riveted and bolted steel-tube
structure with detachable metal panels forward and fabric covering aft.
The horizontal tailplane was strut-braced and the split-type landing
gear, with half-axles hinged beneath the fuselage, was oleo-sprung. The
second prototype (B.534/2) had an enclosed cockpit, an enlarged rudder
and revised landing gear with mainwheel fairings. It established a
Czech national speed record on 18 April 1934, reaching 227.27 mph
Development was held up
when both prototypes were damaged in crash landings during 1934, but
the decision had already been made to orderthe B.534 for the Czech air
arm. The Avia B.534-I, the first production version, closely followed
the design of the second prototype. The prototype's metal propeller was
replaced by a wooden unit and, as on the first prototype, the pilot had
an open cockpit. The main landing gear units were without spats.
Production of the
B.534-1 totalled 46 aircraft. Armament comprised twin fuselage mounted
light machine-guns and two more in fairings on the lower wing.
Production of the Avia B.534-II series reached 100. This version
differed in having all four machine-guns mounted in the fuselage sides,
with consequently enlarged fuselage side blister fairings to house
them. Underwing racks for light bombs were fitted, since the new
fighter was considered suitable also for ground attack. The 46
B.534-III aircraft ordered next had mainwheel fairings, and had the
carburet tor air intake moved forward under the nose. Six of this
version were exported to Greece and 14 to Yugoslavia. The B.534-IV had
an aft-sliding cockpit canopy and raised aft fuselage decking. Total
Czech orders for this version were 253. The Avia Bk.534 was a cannon
armed version, but otherwise similar to the Series IV aircraft. It was
intended that its Hispano-Suiza 12Ycrs engine would have a 20 mm
Oerlikon cannon mounted in the Vee of the engine cylinders, with its
muzzle in the hollow propeller boss. However, as a result of a shortage
of the Oerlikon weapons, many Bk.534s flew with only three
machine-guns, two mounted in the fuselage sides and one in place of the
moteur canon. Some B.534-IV and Bk.534 fighters had the standard
tail skid replaced by a castoring tailwheel.
At the Zurich
International Flying Meet in July 1937, the B.534 demonstrated
excellent manoeuvrability and good overall performance, proving itself
in competition as the outstanding biplane fighter.
By the time of the
Munich crisis in September 1938, B.534s formed the equipment of 21
front line Czech fighter squadrons. After the occupation of the country
by the Germans in March 1939, the puppet Slovak government used some
B.534s in the brief border war with Hungary. Three Slovak squadrons
subsequently took part in the invasion of the Soviet Union along the
Ukrainian Front, but by mid-1942 all had been re-equipped and the type
was relegated to training. During the winter of 1939-40, 8ulgaria
received 72 B.5345, which equipped five fighter squadrons. These were
retained on Bulgarian territory and their only combat sorties were
against Consolidated B.24 Liberator bombers returning from the
disastrous 'Tidal Wave' bombing raid on Ploesti oilfields in Romania,
on 1 August 1943, The B.534s were handicapped by their inadequate
performance and soon afterwards were replaced by French-built Dewoitine
The Luftwaffe used
other B.534s and Bk.534s as advanced trainers and as tow-planes for
training gliders. Some were fitted with all-round-vision cockpit
canopies and others, with arrester hooks, were used for deck landing
trials and training in connection with the aircraft carrier 'Graf
Zeppelin', which was launched but never completed. Finally, three Avias
were used by the insurgents at Tri Duby airfield during the Slovak
National Rising in the late summer of 1944. Two were lost on the ground
during Luftwaffe raids and the third was burned to prevent it from
falling into German hands.
The remarkable Avia
B.534 is commemorated by a remarkably accurate full-scale replica,
completed in 1975, and currently on proud display at the Air Force and
Army Museum at Prague-Kbely.
Avia B.234 - A projected re-engined development of the B.34, but never
Avia B.334 - A second
projected re-engined development of the B.34, but never built.
Avia B.434 - A third
projected re-engined development of the B.34, but never built.
Avia B.634 - Ordered as
a 'cleaned up' development of the B.534 in 1935, the B.634 appeared as
an aerodynamically refined aircraft, with carefully streamlined and
spatted cantilever main landing gear legs. The upper wing had greater
chord than that of the B.534, while that of the lower wing was reduced
in comparison with that of the B.534, and the amount of wing stagger
was also lessened. Despite careful overall attention to streamlining,
increased weight resulted in only marginal performance improvements.
Data includes a powerplant of one Avia-built 850 hp (634 kW) Hispano-Suiza
HS 12Ycrs inline engine, with a maximum speed 415km/h (258 mph),
initial climb 960 m (3,150 ft) per minute, range 500 km (310 miles),
empty weight 1710 kg (3,770 lbs), span 9.40 m (30 ft 10 in) and length
8.35 m (27 ft 4 3/4 in)
850 hp (634 kW) Hispano-Suiza HS 12Ydrs inline piston engine.
Maximum speed 245 mph (394 km/h) at 14,435 ft (4400 m); cruising speed
214 mph (345 km/h); initial climb rate 2,953 ft (900 m) per minute;
service ceiling 34,775 ft (10600 m).
Range: 360 miles
(580 km) on internal fuel.
equipped 3,219 lbs (1460 kg) with a maximum take-off weight of 4,674
lbs (2120 kg).
30 ft 10 in (9.40 m); length 26 ft 10 3/4 in (8.20 m); height 10 ft 2
in (3.10 m); wing area 253.61 sq ft (25.56 sq m).
fixed 7.7 mm (0.303 in) synchronised Model 30 machine-guns in the
forward fuselage, plus up to six 44 lbs (20 kg) bombs on underwing
B.534/1, B.534/2, B.534-I, B.534-II, B.534-III, B.534-IV, Bk.534,
B.234, B.334, B.434, B.634.
flight (B.534/1) August 1933; (B.534/2) set Czech speed record 18 April
Czechoslovakia, Greece (6), Yugoslavia (14), Bulgaria (72), Germany