One 335kW (450shp) (283kW/380shp max continuous rated) Allison 250C20R/2 turboshaft driving a three blade main rotor and two blade tail rotor. Option of one 460kW (615shp) Pratt & Whitney Canada PW200/9 turboshaft.
Allison engine - Max speed 232km/h (125kt), normal cruising speed 200km/h (108kt). Initial rate of climb 1973ft/min. Service ceiling 17,820ft. Max range with standard fuel and no reserves 860km (464nm). Endurance 5hr 8min.
Allison engine - Empty 850kg (1874lb), max takeoff (internal load) 1600kg (3527lb), max takeoff with sling load 1800kg (3968lb).
Main rotor disc diameter 9.00m (29ft 6in), length overall rotors turning 10.55m (34ft 8in), fuselage length including tailskid 9.08m (29ft 9in), height overall 3.05m (10ft 10in). Main rotor disc area 63.6m2 (684.8sq ft).
Standard seating for four or five (including pilot). In medevac configuration accommodation for one stretcher patient and two medical attendants. Max sling load 750kg (1655lb).
Two flying prototypes and one static prototype built by 1998. First deliveries planned during 1999.
Light utility helicopter
The origins of PZL Swidnik's SW4 five seat light utility helicopter date back to the early 1980s.
Swidnik began development of a new four/five place light utility helicopter in 1981. This original SW4 was to have been powered by a 300kW (400shp) PZL Rzeszow GTD350 turboshaft and was built in mockup form. It would have had a top speed of 240km/h (130kt) and a max range with auxiliary fuel of 900km (485nm).
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.