PZL S-4 Kania

PZL S-4 Kania
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S-4 Kania-3 at the Polish Aviation Museum
Type	Trainer and glider towing aircraft
Manufacturer	WSK-Mielec
Maiden flight	17 May, 1951 (S-3)
Primary user	Aeroklub Polski
Produced	1951-1964
Number built	4 (3 S-4 + 1 S-3)

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 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 S-4 Kania-2, was flown. On 19 September 1958, another further improved prototype, the 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 were suspended. It was completed only in 1964 by the Aircraft Repair Works in Krosno.

Operational history

The first S-4 Kania2 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

Template:POL

• Aeroklub Polski operated two S-4 prototypes in Mielec and the third S-4 prototype in Krosno.

Survivors

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

Specifications (S-4)

Description

Wooden construction high-wing parasol monoplane, 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.

General characteristics

• Crew: 1, instructor
• Capacity: 1, student
• Length: 8.72 m (28 ft 7¼ in)
• Wingspan: 12.16 m (39 ft 10⅝ in)
• Height: 2.35 m (7ft 8½ in)
• Wing area: 19.7 m² (212 ft²)
• Empty weight: 660 kg (1,452 lb)
• Loaded weight: 945 kg (2,079 lb)
• Powerplant: 1× Shvetsov M-11D air-cooled 5-cylinder radial engine, 92 kW (125 hp)

Performance

• Maximum speed: 171 km/h (92 kt, 106 mph)
• Stall speed: 63 km/h (34 kt, 39 mph)
• Range: 580 km (313 nm, 360 mi)
• Service ceiling: 5,100 m (16,700 ft)
• Rate of climb: 4.5 m/s (890 ft/min)

References

• PZL S-4 Kania at Poser site
• Janusz Babiejczuk, Jerzy Grzegorzewski: Polski przemysł lotniczy 1945-1973, Warsaw 1973 (Polish language)

See also

Designation sequence

• PZL S-1 - S-3 - S-4

See also

• PZL Kania

External links

• Photos in Ugolok Neba site

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "PZL S-4 Kania".