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had span and area increased by about 5%. Extended exposure to novice pilots revealed a tendency to enter a spin at high angles of attack caused by over-sensitive elevators. Several proposed solutions were tested and in the later 1930s, the problem was successfully resolved when all Wrona bis had
233:
in 1939, with about 100 built at Kocjan's
Warsztaty Szybowcowe factory and another 250 built under licence in at least seven other European countries. Construction drawings, materials and parts were sold, with at least 50 aircraft built by clubs and similar organizations.
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It is not surprising that a basic trainer set no major records; but in June 1938, a Wrona bis made a 6.5 km (4.0 mi; 3.5 nmi) cross-country flight, a first (and last) record for an open girder glider in Poland. In April 1935 another, accompanied by a
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with a deep cut-out for rudder movement. Fixed tail surfaces were ply-covered and the control surfaces fabric-covered. Wronas landed on a tandem pair of sprung skids on the lower longeron.
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Superseded Wrona in 1934 production with a wing of greater span and area. Modified in the late 1930s to overcome over-sensitive elevators and associated spinning tendencies.
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Only one or two survived the war. One Wrona bis remained in use until 1950, after which it became a museum exhibit. In
December 1963 it was acquired by the
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The early Wronas had a wing with a span of 8.8 m (28 ft 10 in) and area of 13.2 m (142 sq ft) but by 1934 the revised
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flown in 1931. Both were simple, high-wing and open frame (flat, uncovered girder fuselage) gliders in the style of the earlier
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of the open-frame fuselage were joined together with vertical and diagonal braces. The pilot sat, unprotected, under the wing
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174:. On each side a pair of parallel struts braced the spars to the lower fuselage. Long, rectangular
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Its two-part wing, mounted on top of the fuselage, was rectangular in plan and built around two
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funding five pre-production airframes were built by
Warsztaty Szybowcowe, the first flying from
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their elevator areas reduced, together with a tailplane of increased area set at a negative
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170:-covered ahead of the forward spar, forming a torsion-resistant D-box, with the rest
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extended above and between the longerons and carried a tall, nearly rectangular
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after its designer, was the most numerous and widely used Polish pre-war
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1.2 m/s (240 ft/min) at 48 km/h (30 mph; 26 kn)
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on a seat on the forward vertical brace. Aft, the Wrona's triangular
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which reached down to the lower longeron. Its narrow, triangular
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Designed by Antoni Kocjan, the Wrona was in competition with the
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Wrona production began in 1933 and continued up to the
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Aviation
Museums and Collections of Mainland Europe
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242:, made the first winch launchings in the country.
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473:. Air Britain (Historians) Ltd. p. 426.
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350:11 at 50 km/h (31 mph; 27 kn)
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265:Prototypes and 1933 production variant.
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362:45 km/h (28 mph; 24 kn)
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399:. London: Putnam Publishing. p.
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311:9.31 m (30 ft 7 in)
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323:13.9 m (150 sq ft)
305:5.6 m (18 ft 4 in)
317:1.9 m (6 ft 3 in)
155:on 30 September 1932 piloted by
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253:, where it remains on display.
1:
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501:Aircraft first flown in 1932
7:
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178:reached from strut to tip.
138:Czerwiński and Jaworski CWJ
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449:"Wrona, 1932 (WS "Wrona")"
278:Specifications (Wrona bis)
112:Warsztaty Szybowcowe Wrona
395:Polish Aircraft 1893-1939
335:150 kg (331 lb)
240:Warsztaty Lotnicze Czajka
116:
32:
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329:75 kg (165 lb)
506:1930s Polish sailplanes
290:General characteristics
247:Polish Aviation Museum
132:Design and development
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117:Glider Workshops Crow
105:
70:Warsztaty Szybowcowe
391:Cynk, Jerzy (1971).
348:Maximum glide ratio:
181:The upper and lower
469:Ogden, Bob (2009).
225:Operational history
511:High-wing aircraft
425:"Kocjan Wrona bis"
231:Invasion of Poland
219:angle of incidence
157:Mieczysław Jonikas
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480:978-0-85130-418-2
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86:6 September 1932
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49:Type of aircraft
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56:National origin
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360:Minimum speed:
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172:fabric-covered
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126:primary glider
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96:more than 430
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78:Antoni Kocjan
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410:0-370-00085-4
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354:Rate of sink:
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333:Gross weight:
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106:Wrona in 1937
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83:First flight
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67:Manufacturer
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452:. Retrieved
428:. Retrieved
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191:leading edge
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122:Kocjan Wrona
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92:Number built
454:11 December
430:22 December
341:Performance
495:Categories
367:References
321:Wing area:
33:Wrona bis
309:Wingspan:
297:Capacity:
283:Data from
270:Wrona bis
214:Worna bis
207:elevators
203:tailplane
183:longerons
166:. It was
75:Designer
285:Samoloty
257:Variants
176:ailerons
41:primary
315:Height:
303:Length:
221:(-2º).
168:plywood
153:Mokotów
147:. With
145:Zögling
43:trainer
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401:710-11
251:Kraków
199:rudder
187:chords
142:German
120:), or
61:Poland
46:glider
19:Wrona
262:Wrona
164:spars
38:Role
475:ISBN
456:2018
432:2018
405:ISBN
149:LOPP
110:The
299:One
249:in
195:fin
185:or
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440:^
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375:^
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114:(
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