The prototype of the first multi-purpose helicopter designed and built in Poland.
In 1953, engineer Bronislaw Zurakowski, who had designed Poland’s first experimental helicopter SP-GIL at the Institute of Aviation a few years earlier, developed a design for a four-seat, multi-purpose helicopter. Initially the project was named GIL-4, later changed to BZ-4 Zuk. The prototype of the new helicopter, powered by the Polish WN-4 engine (a PZL WN-3 adapted for helicopter use), was not completed until 1956.
On 10 February 1959, the BZ-4 Zuk made its first flight, piloted by Ryszard Witkowski, MSc Eng. Trials, during which the helicopter made 17 flights totalling 3 hours and 40 minutes, continued until August 1959. Unfortunately, the trials were not without damage.
After the last incident, despite repairing the airframe, further work on the helicopter was abandoned, and two additional prototypes were never completed. The Soviet Mi-1 helicopter was selected for series production instead, manufactured under the designation SM-1 at the WSK-Swidnik factory. The authorities used the BZ-4 accident as a pretext to terminate the domestic helicopter development programme.
The only completed prototype was subsequently transferred to the Museum, however stripped of many parts (including the engine, parts of the cabin glazing, and the instrument panel). In the late 1980s, the possibility of restoration was considered, but returning the helicopter to its historical condition was deemed impossible.
| Rotor diameter | 12.0 m |
| Fuselage length | 10.55 m |
| Takeoff weight | 1500 kg |
| Maximum speed | 156 km/h |
| Ceiling | 3000 m |
| Range | 260 km |
| Armament | – |
| Engine | 7-cylinder radial air-cooled Narkiewicz WN-4, 320 hp (237 kW) |
