RWD-21

infobox Aircraft
name =RWD-16bis / RWD-21
type =Touring and sports plane
manufacturer =DWL
national origin = Poland



caption =RWD-21 in the Polish Aviation Museum
designer = RWD bureau
first flight =1938 (RWD-16bis)
introduced =1938
retired =1950
status =
primary user =Poland
more users =
produced =1938-1939
number built =>9
unit cost =
developed from =RWD-16 The RWD-16bis and RWD-21 were Polish two-seat low-wing touring and sports planes of the late 1930s, constructed by the RWD bureau, sharing the same construction, main difference of the RWD-21 being a stronger engine.

Development

The RWD-16bis was designed in 1938 by Andrzej Anczutin of the RWD bureau as a light and economical touring and sports plane, utilizing the experience from an unsuccessful earlier design RWD-16. In spite of the designation, the RWD-16bis design was new, only partly basing on the RWD-16 construction. On contrary, it appeared a successful design, with good handling and performance and ease of flying. It was a wooden low-wing monoplane, with two seats side-by-side in a closed cockpit.

The first prototype was built and first flown in June-July 1938 (registration SP-BNM) followed by the second prototype (SP-BPC). Both were powered by a Polish-designed 63 hp Avia 3 straight engine. In series, a 62 hp Walter Mikron II straight engine was expected. The LOPP paramilitary organization ordered 20 aircraft, the first were to be built by May 1939. Probably a few were completed by the outbreak of the World War II, but there are no evidences [http://rwd-dwl.net/samoloty/rwd_16_bis/index.htm Gujski, Robert: "RWD-16 bis"] - retrieved on 27-5-2008] .

The RWD-21 was a development variant with a stronger 90 hp engine Cirrus Minor and some minor changes, mostly to a canopy. The prototype was flown in February 1939 (registration SP-BPE). The first series of 10 aircraft was ordered and at least six were completed and registered before the war outbreak (SP-BRE, BRF, BRG, BRH, BRM, KAR) [ [http://rwd-dwl.net/produkcja/produkcja_6.htm Gujski, Robert: "Produkcja samolotów i szybowców w S.L. i D.W.L."] - retrieved on 27-5-2008]

Operational history

Both aircraft were found by the LOPP paramilitary organization as successful economical planes, suitable for the plan of subsiding a development of the private aviation in Poland. A series of RWD-16bis was ordered by the LOPP at a price of 17,800 złoty (including the engine 6,200 zł), in order to sell airframes to private owners for 9,500 zł (the price of a mid-class car), lending the engine. The price of the RWD-21 was 20,500 zł (including the engine 8,000 zł).

At the outbreak of World War II, one RWD-21 was owned by Wilno Aero Club (SP-BRF), three by the LOPP (SP-BRE, BRG, BRH), one by private owner (SP-KAR) and two remained in the factory (SP-BPE, BRM) [http://rwd-dwl.net/rejestr/index.htm Gujski, Robert: "Skrzydła Polski"] - retrieved on 27-5-2008] . After the German invasion on Poland, in September 1939, two RWD-21s (SP-BPE and BRM) were evacuated from the factory to Romania (one of them by a glider pilot Bronisław Żurakowski, who had not flown a plane before). At least one of them (SP-BPE) was used in Romania with markings YR-VEN and returned to Poland after the war. It was next used until mid-1950s with new markings SP-AKG. It is currently restored and preserved in the Polish Aviation Museum in Kraków.

One RWD-21 was evacuated to Latvia, its further fate is unknown.

Description

Wooden construction low-wing cantilever monoplane, conventional in layout, with a fixed landing gear and a closed cockpit. Fuselage semi-monocoque, plywood-covered, duralumin in front engine section. Single-part trapezoid wings with rounded tips, two-spar, plywood (in front) and canvas covered, fitted with split flaps. Conventional cantilever empennage, plywood (fins) and canvas (elevators and rudder) covered. Two seats side-by-side, with twin controls, under a canopy, with a fixed windshield. Behind a cockpit, a place for a baggage. Conventional fixed landing gear with a rear skid, the main gear in covers. 4-cylinder straight engine in front, driving a two-blade tractor wooden propeller Szomański of a fixed pitch, 1.75 m diameter (RWD-16bis). Fuel tank 73 l in mid-wing section, under the crew seats.

pecifications (RWD-16bis)

aircraft specifications
plane or copter?=plane
jet or prop?=prop
ref=Glass, A. (1977)
crew=1, pilot
capacity=1, passenger or co-pilot
payload main=
payload alt=
length main= 7.9 m
length alt=
span main= 11 m
span alt=
height main= 2.27 m
height alt=
area main= 14.95 m²
area alt=
airfoil=
empty weight main= 385 kg
empty weight alt=
loaded weight main= 615 kg
loaded weight alt=
useful load main=230 kg
useful load alt=
max takeoff weight main=
max takeoff weight alt=
more general=
engine (prop)= Walter Mikron II
type of prop=4-cylinder air-cooled inverted straight engine
number of props=1
power main= 62 hp
power alt= 44 kW
power original=
max speed main=180 km/h
max speed alt=
cruise speed main=155 km/h
cruise speed alt=
stall speed main=70 km/h
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main= 700 km
range alt=
ceiling main=4,150 m
ceiling alt=
climb rate main= 3.1 m/s
climb rate alt=
loading main= 41.1 kg/m²
loading alt=
power/mass main=
power/mass alt=
more performance=
armament=
avionics=

pecifications (RWD-21)

aircraft specifications
plane or copter?=plane
jet or prop?=prop
ref=Glass, A. (1977)
crew=1, pilot
capacity=1, passenger or co-pilot
payload main=
payload alt=
length main= 8.4 m
length alt=
span main= 11 m
span alt=
height main= 2.12 m
height alt=
area main= 14.95 m²
area alt=
airfoil=
empty weight main= 425 kg
empty weight alt=
loaded weight main= 660 kg
loaded weight alt=
useful load main=235-260 kg
useful load alt=
max takeoff weight main= 685 kg
max takeoff weight alt=
more general=
engine (prop)= Cirrus Minor
type of prop=4-cylinder air-cooled inverted straight engine
number of props=1
power main= 90 hp
power alt= kW
power original=
max speed main=210 km/h
max speed alt=
cruise speed main=180 km/h
cruise speed alt=
stall speed main=72 km/h
stall speed alt=
never exceed speed main=
never exceed speed alt=
range main= 650 km
range alt=
ceiling main=5,500 m
ceiling alt=
climb rate main= 4.7 m/s
climb rate alt=
loading main= 44.1 kg/m²
loading alt=
power/mass main=
power/mass alt=
more performance=
armament=
avionics=

References

*Andrzej Glass: "Polskie konstrukcje lotnicze 1893-1939" ("Polish aviation constructions 1893-1939"), WKiŁ, Warsaw 1977, p.322-323 pl icon

ee also

aircontent
related=
similar aircraft=
*Bücker Bü 181 - LWD Żak
lists=
see also=

External links

* [http://www.airwar.ru/enc/law1/rwd21.html Photos and drawings at Ugolok Neba]