WSK PZL Świdnik SM-4 Łątka. 1962. English version

Kraków July 30. 2018.

179b Section 1962

WSK PZL Świdnik PZL SM-4 Łątka 





The PZL SM-4 Łątka helicopter was made of metal (steel) and composites (glass laminates). Composites were made of support rotor blades, a crew cabin shell, chassis components, a tail-gate balancer and a tail rotor.

Three-blade supporting rotor. The blades had a construction made of laminate. A girder made of a laminate with a polystyrene core. Strainer parts made of honeycomb filler were attached to the core. The whole was covered with a laminate. The blades had steel fittings at the base for connection to the rotor head. Fittings were able to move vertically and horizontally for control.

Two-blade tail propeller. Made in the same way as the main rotor. A tail propeller drive shaft was placed above the tail beam. The drive shaft consisted of five sections connected by joints.

The helicopter was made of three main sections: the cabin, the middle section, the tailbone. The cabin skeleton was made of laminate. The windows are made of organic glass. The cabin was attached to a beam that was a floor and was made of duralumin. The cabin floor connected to the truss of the central part with four fittings. The central part of the helicopter was a truss made of steel pipes connected by welding. In this part there is a main transmission, a motor with a fan, a fuel tank and others. The tail beam was a truss made of steel pipes.

The chassis consisted of skids, fixed. The skids were made of dural pipes.

WN-6S piston engine, air-cooled, six-cylinder with 132 kW (180 hp) starting power.

General characteristics of PZL SM-4 Łątka (Data T-T)

Fuselage length: 9.30 m

Height 2.80 m

Diameter of the rotor: 10.00 m (32 ft 10 in)

Main rotor surface: 78.5 m2 (845 m²)

Own weight: 640-660 kg (1 455 lb)

Useful weight: 340 kg

Starting weight: 970-980 kg

Maximum take-off weight: 1000 kg (2205 pounds)

Maximum speed: 115 km / h (71 mph, 62 kn) (estimated)

Range: 300 km (186 miles, 162 miles) (estimated)

Ceiling: 3300 m (10 800 ft) (estimates)

The rate of climb: 4.4 m / s (870 ft / min) (estimate)

Flight duration: 3 hours 20 minutes (estimated)

Drive unit: 1 × WN-6S air-cooled, six-cylinder, counter-rotating piston engine, 130 kW (180 HP)

Crew: 1

Capacity: 2 passengers

One prototype was built.


Written by Karol Placha Hetman