PZL S-4 Kania

infobox Aircraft
name =PZL S-4 Kania
type = Trainer and glider towing aircraft
manufacturer =WSK-Mielec



caption =S-4 Kania-3 at the Polish Aviation Museum
designer =
first flight =17 May, 1951 (S-3)
introduced =
retired =
status =
primary user = "Aeroklub Polski"
more users =
produced = 1951-1964
number built = 3 + 1
unit cost =
variants with their own articles =

The PZL S-4 Kania was a Polish trainer and glider towing aircraft of 1950s, not built in series. The first prototype was designated S-3 Kania. There is also a helicopter named PZL Kania.

Design and development

The aircraft was designed by Eugeniusz Stankiewicz in 1950, its primary purpose was towing gliders. The first prototype was named S-3 Kania ("kite" (bird), S for Stankiewicz, it probably had no PZL prefix). It was built in the "Szybowcowe Zakłady Doświadczalne" (SZD, Glider Experimental Works) in Bielsko-Biała and first flew on 17 May, 1951. It appeared quite successful, and was cheaper in production and service, than the CSS-13 (licensed Polikarpov Po-2), but was not produced, because the Aviation Institute ("Instytut Lotnictwa", IL) found some lacks in calculations and too weak landing gear. The work ceased, while the prototype was abandoned to ruin.

In 1956, the design was taken over by WSK-Mielec factory (partly due to an interest of the press, combined with shortages of aircraft in aero clubs). It was developed and improved by Stankiewicz's team and on 2 September 1957, a new prototype, the PZL S-4 Kania-2, was flown. On 19 September 1958, another further improved prototype, the PZL S-4 Kania-3, flew, with enlarged tailfin. This underwent state trials in 1960 with good results. It offered good handling and was useful to training, glider towing, and basic aerobatics. It could tow 2 or 3 gliders at a time. The S-4 did not enter production, though, because due to a long development, the design had become dated. At that time, it was preferred to use metal aircraft in aeroclubs, and the PZL-104 Wilga was in development. The other thing was, production of the obsolete M-11 engine had ceased in Poland.

Work on the third S-4 prototype was suspended. It was completed only in 1964 by the Aircraft Repair Works in Krosno.

Operational history

The first S-4 "Kania-2" prototype (registration SP-PAA) was shown on World Glider Championships in Leszno in 1958, among others it hauled several gliders. Along with the second S-4 prototype (registration SP-PBB), it was used by the aero club in Mielec. The third S-4 prototype was used in Krosno (registration SP-PBE). The second prototype was written off in the end of 1970, the rest around the same.

Operators

;POL
*"Aeroklub Polski" operated two S-4 prototypes in Mielec and the third S-4 prototype in Krosno.

urvivors

The second prototype S-4 Kania-3 (SP-PBB) is preserved in the Polish Aviation Museum in Kraków, from 1971.

pecifications (S-4)

Description

Wooden construction high-wing monoplane (parasol wing), conventional in layout. Semi-monocoque fuselage. Crew of two, sitting in tandem, in open cockpits with windshields. Fixed conventional landing gear. Two-blade propeller. Fuel tanks 165 l.

aircraft specifications
plane or copter?=plane
jet or prop?=prop
crew=1, instructor
capacity=1, student
length main=8.72 m
length alt=28 ft 7¼ in
span main=12.16 m
span alt=39 ft 10⅝ in
height main=2.35 m
height alt=7ft 8½ in
area main=19.7 m²
area alt=212 ft²
empty weight main=660 kg
empty weight alt=1,452 lb
loaded weight main=945 kg
loaded weight alt=2,079 lb
useful load main=
useful load alt=
max takeoff weight main=
max takeoff weight alt=

engine (prop)=Shvetsov M-11D
type of prop= air-cooled 5-cylinder radial engine
number of props=1
power main= 125 hp
power alt=92 kW

max speed main=171 km/h
max speed alt= 92 kt, 106 mph
cruise speed main=
cruise speed alt=
stall speed main= 63 km/h
stall speed alt= 34 kt, 39 mph
range main=580 km
range alt= 313 nm, 360 mi
ceiling main=5,100 m
ceiling alt= 16,700 ft
climb rate main=4.5 m/s
climb rate alt=890 ft/min
loading main=
loading alt=
thrust/weight=

armament=

ee also

aircontent
related=
*PZL S-1
similar aircraft=

lists=

see also=
*PZL Kania

References

* [http://www.powiat.mielec.pl/poser/samoloty/pzl_s-x/s4.htm PZL S-4 Kania] at Poser site
*Janusz Babiejczuk, Jerzy Grzegorzewski: "Polski przemysł lotniczy 1945-1973", Warsaw 1973 (Polish language)

External links

* [http://www.airwar.ru/enc/la/s4.html Photos] at Ugolok Neba site