PZL SW-4

The PZL SW-4 Puszczyk (pl. Tawny Owl) is a Polish light single-engine multipurpose helicopter manufactured by PZL-Świdnik.

Development

The origins of PZL-Swidnik's SW4 five seat light utility helicopter date back to the early 1980s.

PZL-Swidnik began development of a new four/five place light utility helicopter in 1981. This original SW4 was to have been powered by a 300 kW (400 shp) PZL Rzeszow GTD350 turboshaft and was built in mockup form. It would have had a top speed of 240 km/h (130kt) and a max range with auxiliary fuel of 900 km (485 nm).

The collapse of the Iron Curtain allowed Swidnik to substantially redesign the SW4, based around the Allison 250 turboshaft. Aside from the powerplant, design changes included a more streamlined fuselage and revised tail and tailboom.

The first prototype, a non flying ground test aircraft, was rolled out in December 1994. Two flying prototypes have been built, the first of which was completed in 1996 and first flew on October 26 that year.

PZL-Swidnik aims to attain US FAA FAR Part 27 certification for the SW4 which will allow it to enter production in 1999. The program was delayed somewhat when PZL Swidnik decided to redesign the rotor head, enlarge the horizontal stabiliser and improve the hydraulic system.

Once the basic Allison powered SW4 is certificated and in production PZL Swidnik aims to offer a Pratt & Whitney Canada PW200-powered variant. A twin engine model is also planned to allow the helicopter to meet forthcoming European regulations which will restrict single engine helicopter operations under some conditions.

The SW4 is expected to be able to fulfil a range of utility missions ranging from executive transport to medevac and police roles. Border patrol and military pilot training are other planned missions.

In 2006, PZL-Świdnik entered into agreement with China's Jiujiang Hongying Technology Development Ltd to co-produce the SW4 at Jiujiang, China, with sight set on the international market for SW4. The maiden flight of the first SW4 co-produced in China took place on 25 Feb 2010.^[2]

In 2011 development of the RUAV (Rotorcraft Unmanned Aircraft Vehicle) version was started.^[3] It was first shown at the MSPO 2012 in Poland as "SW-4 Solo" RUAS/OPH platform (Rotorcraft Unmanned Air System/Optionally Piloted Helicopter) and is expected to first fly in 2013.^[4]

Design

PZL SW-4 #0203 of Polish Air Force

One 335 kW (450 shp) (283 kW/380 shp max continuous rated) Allison 250C20R/2 turboshaft driving a three blade main rotor and two blade tail rotor. Option of one 460 kW (615 shp) Pratt & Whitney Canada PW200/9 turboshaft.

Allison engine - Max speed 232 km/h (125 kt), normal cruising speed 200 km/h (108 kt). Initial rate of climb 1973 ft/min. Service ceiling 17,820 ft (5,430 m) Max range with standard fuel and no reserves 860 km (464 nmi). Endurance 5hr 8min.

Operators

 Poland

• Polish Air Force^[5]

Specifications (SW-4)

Data from {name of first source}

General characteristics

• Crew: one, pilot
• Capacity: 4 passengers
• Length: 10.57 m (34 ft 8 in)
• Rotor diameter: 9.00 m (29 ft 6 in)
• Height: 3.05 m (10 ft 0 in)
• Disc area: 64 m² (684 ft²)
• Empty weight: 1,050 kg (2,310 lb)
• Loaded weight: 1,600 kg (3,520 lb)
• Max. takeoff weight: 1,800 kg (3,960 lb)
• Powerplant: 1 × Allison 250-C20R/2 turboshaft engine, 336 kW (457 shp)

Performance

• Maximum speed: 260 km/h (141 knots, 162 mph)
• Range: 790 km (427 nmi, 493 mi)
• Service ceiling: 5,200 m (17,056 ft)
• Rate of climb: 618 m/min (2,027 ft/min)
• Disc loading: 3.4 kg/m² (0.7 lb/ft²)
• Power/mass: 0.21 kW/kg (0.13 hp/lb)

See also

Related development

• Bell 206
• Cicaré CH-14
• Eurocopter Colibri
• Schweizer 333

Related lists

• List of helicopter models

References

External links

Wikimedia Commons has media related to SW-4.

• List of all SW-4 helicopters used by Polish Air Force
• Description on manufacturer's page
• SW-4 Production list, Program history
• SW-4 Photo gallery