RWD-4

infobox Aircraft
name =RWD-4
type =Sports plane
manufacturer =Warsaw University of Technology workshops



caption =
designer = RWD team
first flight =Spring 1930
introduced =1930
retired =1936
status =
primary user =Poland
more users =
produced =1930
number built =9
unit cost =
variants with their own articles = The RWD-4 was a Polish sports plane of 1930, constructed by the RWD team.

Development

The RWD-4 was constructed by the RWD team of Stanisław Rogalski, Stanisław Wigura and Jerzy Drzewiecki in Warsaw. It was based upon their earlier RWD-2 design, but enlarged and fitted with more powerful inline engine. It retained the same fish-shaped fuselage without a direct view forward from the pilot's seat, though the view improved due to thin fuselage profile before the pilot. Also a silhouette became slimmer. The aircraft development was ordered by the Ministry of Communication especially for participation in the Challenge 1930 international air competition. At the same time, the RWD developed similar liaison aircraft project, the RWD-3, which shared many features with the RWD-4.

The first three aircraft (registration SP-ADK, -ADL and -ADM) were completed and flown by the designer Jerzy Drzewiecki in early 1930. In late 1930, a further six aircraft were built for the Polish Aero Club (registration SP-AEK, -AEL, AEY, -AEZ, -AFC, -AGP).

ervice

The first three aircraft took part in the Challenge 1930 competition in July. Only Jerzy Bajan completed the race on SP-ADM on the 32nd place (of 35 classified and 60 starting crews). Franciszek Żwirko (flying with Stanisław Wigura) withdrew due to engine failure, while the third pilot Tadeusz Karpiński withdrew due to illness.

RWD-4s were later used in Polish local air competitions, with some success (for example, F. Żwirko won the 3rd Polish Light Aircraft Contest in 1930, and other RWD-4s took the 2nd, 5th and 6th place). In 1931, in an international air meeting in Zagreb, Jerzy Bajan won 2nd place overall and the 1st place in aerobatics. RWD-4s were also used for training and glider towing in regional aero clubs. The first two were withdrawn in 1931, the last were scrapped in 1936, after quite short, but meritorious service in Polish sporting aviation.

Description

Wooden construction sports plane, conventional in layout, high-wing cantilever monoplane. The fuselage rectangular in cross-section (narrower in upper part), plywood-covered. Trapezoid one-part wing, canvas and plywood covered. A crew of two, sitting in tandem in the fuselage, with dual controls. The cockpits were open to the sides, with individual doors on the right. Principally powered by a 4-cylinder air-cooled 115 hp Cirrus Hermes straight engine (105 hp nominal power, 115 hp take-off power), driving a two-blade wooden propeller, the aircraft was also known to be fitted with 85 hp Cirrus III and 105 hp de Havilland Gipsy II engines. Landing gear was conventional, fixed, with a rear skid. The fuel tank capacity was 110 litres held in-wing giving fuel consumption of 21 litres per hour.

pecifications (RWD-4)

aircraft specifications
plane or copter?= plane
jet or prop?= prop
ref=Glass, A. (1977)
crew= One, pilot
capacity=One, passenger, student or second pilot
length main= 7.0 m
length alt= 22 ft 11 in
span main= 10.5 m
span alt= 34 ft 5 in
height main= 2.26 m
height alt= 7 ft 5 in
area main= 15.0 m²
area alt= 161.5 ft²
airfoil=
empty weight main= 398-420 kg
empty weight alt= 875-924 lb
loaded weight main= 700 kg
loaded weight alt= 1,540 lb
useful load main= 280-382 kg
useful load alt=
max takeoff weight main= 780 kg
max takeoff weight alt= 1,716 lb
more general=
engine (prop)= Cirrus Hermes
type of prop= 4-cylinder air-cooled straight engine
number of props=1
power main= 115 hp
power alt= 86 kW
power original=
max speed main= 180 km/h
max speed alt= 97 knots, 112 mph
cruise speed main= 160 km/h
cruise speed alt=
never exceed speed main=
never exceed speed alt=
stall speed main= 75 km/h
stall speed alt=
range main= 800 km
range alt= 432 nm, 497 mi
ceiling main= 5,000 m
ceiling alt= 16,400 ft
climb rate main= 4.6 m/s
climb rate alt= 905 ft/min
loading main= 46.5 kg/m²
loading alt= 9.5 lb/ft²
thrust/weight=
power/mass main=
power/mass alt=
more performance=
*Take-off run: 110 m
*Take-off run at 8.5 m gate: 243 m
armament=
avionics=

ee also

aircontent
related=
*RWD-1 - RWD-2 - RWD-3 - RWD-5 - RWD-7
similar aircraft=

lists=

see also=

References

* Glass, Andrzej: "Polskie konstrukcje lotnicze 1893-1939" ("Polish aviation constructions 1893-1939"), WKiŁ, Warsaw 1977 pl icon

External links

* [http://rwd-dwl.net/samoloty/rwd_4/index.htm Photos and description (in Polish)]