The PZL.4 was a Polish three-engine passenger aircraft for 10 passengers, built in PZL factory in 1932, which remained a prototype. It was the first Polish-designed and produced multi-engine plane.
Despite purchasing a number of three-engine Fokker F.VIIb/3m aircraft, LOT Polish Airlines soon started looking for a more modern design and organized a design contest in 1928. The contest was won by the Polish engineer Zygmunt Bruner, working in the French Bernard works, with his design T-600. It was an all-metal high-wing three-engine monoplane, similar to Ford Trimotor. State Aviation Works PZL decided to take over its development, and a group of engineers was sent to Paris and worked the design in 1929, under direction of Zygmunt Bruner. There were also carried out aerodynamic trials of a plane model. Detailed technical drawings were worked in PZL in Warsaw in 1930, under direction of Stanisław Prauss, and a prototype was built, designated PZL.4 (this designation was used before for a single-engine design worked out for a passenger plane contest in 1928, won by PWS-20).
The PZL.4 was a high-wing cantilever monoplane of metal construction, with closed cab and three engines. The fuselage was rectangular in cross-section, made of duralumin and covered with duralumin sheet. The two-spar wings and tailfins were covered with Wibault-pattern ribbed duralumin sheet. The wings had squared-off wingtips. A crew of two (pilot and mechanic), were accommodated in front, before the wing, equipped with twin controls. Behind and slightly below under the wing, there was a cabin for 10 passengers in three compartments in the fuselage. The cabin had wide rectangular windows, sloped outwards for a better view, and door on the left side. The cabin had places for a baggage behind it and below a floor.
Three 9-cylinder Polish-Skoda J-5a Whirlwind radial engines mounted in the fuselage nose and in wing nacelles provided (180 kW (240 hp) takeoff power and 160 kW (220 hp) nominal power. The engines were fitted with Townend rings and three-blade metal propellers, later two-blade wooden propellers of a fixed pitch. A conventional fixed landing gear, with a rear wheel, main gear wheels' diameter 1.15 m (3 ft 9 in) was also fitted. The fuel tank capacity of 915 L (242 US gal; 201 imp gal) in wing centre-section tanks, providing (cruise fuel consumption 180 L/h (48 gal/h; 40 imp gal/h)).
Operational historyedit
The prototype was first flown on 8 January 1932 in Warsaw by Bolesław Orliński (markings SP-AGY). In June 1932 it took part in an international air meeting in Warsaw. From autumn 1932 to 1935 it was evaluated by LOT Polish Airlines, but it was found unsatisfactory. The empty weight was larger by 730 kg, over the design specification, which decreased performance. As a result, its performance was inferior to Fokker F.VIIb/3m, with the same engines. Proposals to use 220 kW (300 hp) Gnome-Rhône 7K or 340 kW (450 hp) Pratt & Whitney R-1340 Wasp engines were rejected by LOT (the latter engines would demand strengthening of construction).
The prototype cost was 1,416,110 złoty and it brought the manufacturer 663,000 złoty loss.[1] The prototype was withdrawn from service in 1936 and scrapped in 1937.
^Cynk, Jerzy (1971). Polish Aircraft 1893–1939. London: Putnam Publishing. pp. 138-141. ISBN0-370-00085-4.
Further readingedit
Glass, Andrzej (1977). Polskie konstrukcje lotnicze 1893-1939" (Polish aviation constructions 1893-1939). Warsaw: WKiŁ. pp. 162–164.
Mazur, Wojciech (2016). Samoloty komunikacyjne PLL LOT. Wielki leksykon uzbrojenia. Wrzesień 1939 (in Polish). Vol. tom 81. Warsaw: Edipresse Polska. ISBN978-83-7945-055-8.
polish, three, engine, passenger, aircraft, passengers, built, factory, 1932, which, remained, prototype, first, polish, designed, produced, multi, engine, plane, role, passenger, aircraft, manufacturer, first, flight, january, 1932, introduction, 1933, retire. The PZL 4 was a Polish three engine passenger aircraft for 10 passengers built in PZL factory in 1932 which remained a prototype It was the first Polish designed and produced multi engine plane PZL 4 Role Passenger aircraft Manufacturer PZL First flight 8 January 1932 Introduction 1933 Retired 1936 Status prototype Primary user Polish civilian aviation LOT Polish Airlines Number built 1 Contents 1 Development 2 Operational history 3 Specifications 4 References 5 Further reading 6 External links 7 See alsoDevelopment editDespite purchasing a number of three engine Fokker F VIIb 3m aircraft LOT Polish Airlines soon started looking for a more modern design and organized a design contest in 1928 The contest was won by the Polish engineer Zygmunt Bruner working in the French Bernard works with his design T 600 It was an all metal high wing three engine monoplane similar to Ford Trimotor State Aviation Works PZL decided to take over its development and a group of engineers was sent to Paris and worked the design in 1929 under direction of Zygmunt Bruner There were also carried out aerodynamic trials of a plane model Detailed technical drawings were worked in PZL in Warsaw in 1930 under direction of Stanislaw Prauss and a prototype was built designated PZL 4 this designation was used before for a single engine design worked out for a passenger plane contest in 1928 won by PWS 20 The PZL 4 was a high wing cantilever monoplane of metal construction with closed cab and three engines The fuselage was rectangular in cross section made of duralumin and covered with duralumin sheet The two spar wings and tailfins were covered with Wibault pattern ribbed duralumin sheet The wings had squared off wingtips A crew of two pilot and mechanic were accommodated in front before the wing equipped with twin controls Behind and slightly below under the wing there was a cabin for 10 passengers in three compartments in the fuselage The cabin had wide rectangular windows sloped outwards for a better view and door on the left side The cabin had places for a baggage behind it and below a floor Three 9 cylinder Polish Skoda J 5a Whirlwind radial engines mounted in the fuselage nose and in wing nacelles provided 180 kW 240 hp takeoff power and 160 kW 220 hp nominal power The engines were fitted with Townend rings and three blade metal propellers later two blade wooden propellers of a fixed pitch A conventional fixed landing gear with a rear wheel main gear wheels diameter 1 15 m 3 ft 9 in was also fitted The fuel tank capacity of 915 L 242 US gal 201 imp gal in wing centre section tanks providing cruise fuel consumption 180 L h 48 gal h 40 imp gal h Operational history editThe prototype was first flown on 8 January 1932 in Warsaw by Boleslaw Orlinski markings SP AGY In June 1932 it took part in an international air meeting in Warsaw From autumn 1932 to 1935 it was evaluated by LOT Polish Airlines but it was found unsatisfactory The empty weight was larger by 730 kg over the design specification which decreased performance As a result its performance was inferior to Fokker F VIIb 3m with the same engines Proposals to use 220 kW 300 hp Gnome Rhone 7K or 340 kW 450 hp Pratt amp Whitney R 1340 Wasp engines were rejected by LOT the latter engines would demand strengthening of construction The prototype cost was 1 416 110 zloty and it brought the manufacturer 663 000 zloty loss 1 The prototype was withdrawn from service in 1936 and scrapped in 1937 Specifications editData from Polish Aircraft 1893 1939 2 General characteristicsCapacity 10 14 passengers Length 16 5 m 54 ft 2 in Wingspan 24 4 m 80 ft 1 in Height 3 3 m 10 ft 10 in Wing area 77 m2 830 sq ft Empty weight 4 081 kg 8 997 lb Gross weight 5 586 kg 12 315 lb Fuel capacity 915 L 242 US gal 201 imp gal Powerplant 3 Polish Skoda J 5a Whirlwind 9 cylinder air cooled radial piston engines 160 kW 220 hp each Propellers 3 bladed Heddernheimer Kupferwerke adjustable pitch metal propellers Performance Maximum speed 190 km h 120 mph 100 kn at sea level 179 km h 111 mph 97 kn at 2 000 m 6 600 ft dd dd dd Range 800 km 500 mi 430 nmi Service ceiling 2 800 m 9 200 ft Time to altitude 1 000 m 3 300 ft 8 minutes 58 seconds 2 000 m 6 600 ft 22 minutes dd dd dd Wing loading 72 6 kg m2 14 9 lb sq ft Power mass 0 0535 hp lb 0 0880 kW kg References edit Mazur 2016 p 13 16 Cynk Jerzy 1971 Polish Aircraft 1893 1939 London Putnam Publishing pp 138 141 ISBN 0 370 00085 4 Further reading editGlass Andrzej 1977 Polskie konstrukcje lotnicze 1893 1939 Polish aviation constructions 1893 1939 Warsaw WKiL pp 162 164 Mazur Wojciech 2016 Samoloty komunikacyjne PLL LOT Wielki leksykon uzbrojenia Wrzesien 1939 in Polish Vol tom 81 Warsaw Edipresse Polska ISBN 978 83 7945 055 8 External links editPhotos and drawings at Ugolok Neba siteSee also edit nbsp Wikimedia Commons has media related to PZL 4 nbsp aviation portal Aircraft of comparable role configuration and era Fokker F VIIb 3m Ford Trimotor Retrieved from https en wikipedia org w index php title PZL 4 amp oldid 1169471132, wikipedia, wiki, book, books, library,
