|BŻ-1 Gil at the Polish Aviation Museum|
|Manufacturer||Główny Instytut Lotnictwa|
|First flight||4 April 1950|
The BŻ-1 GIL was the first Polish experimental helicopter, constructed in 1950. Developed by the Main Aviation Institute (Warsaw), the only constructed GIL saw service until 1960 when it was irreparably damaged and subsequently decommissioned. The prototype aircraft currently resides at the Polish Aviation Museum.
Design and development
The helicopter was designed at the research institute Główny Instytut Lotnictwa - Main Aviation Institute in Warsaw, from an initiative of Zbigniew Brzoska. The Polish aviation industry was destroyed after World War II, and in addition, the principal of the institute Władysław Fiszdon was the only person who had seen a helicopter (Sikorsky R-4 in England).
Despite severe material shortages, work on the experimental design started in 1948, and the main designer became Bronisław Żurakowski (brother of test pilot Janusz Żurakowski), who designed the helicopter rotor and the control system. It used simpler Hiller rotor type, with two auxiliary blades. The structure of the fuselage, tail boom, auxiliary rotor and tricycle undercarriage were designed by Tadeusz Chyliński. The power unit and final drive were designed by Zbigniew Brzoska. The design utilized some components left by the Germans, like a piston engine Hirth HM 504 (re-configured for vertical use), rear gear from a Zündapp motorcycle and wheels from a DFS Kranich glider's jettisonable landing gear.
Initially, the helicopter had no name. It only received the registration letters SP-GIL, from the institute abbreviation, and soon it became known as GIL (gil also means bullfinch in Polish). Later it was also given the designation BŻ-1, from Żurakowski's initials.
The helicopter was completed by the end of 1949. During the first flight trial on 14 January 1950, it was overturned by a wind gust and had to be repaired. The test pilot was Bronisław Żurakowski, who taught himself to fly a helicopter. The helicopter first flew on 4 April 1950, restrained on tethers by two men (Fiszdon and Chyliński) for a measure of safety.
During 1950–1953, it underwent a test program and was often modified. At first it had elastic rotor blades. In 1950, it was fitted with rigid blades and an efficient simple custom-designed resonant vibration eliminator, similar to later Sikorsky designs. During tests, for different reasons, it crashed or was damaged without casualties at least seven times and was repaired each time.
On 20 July 1952, the BŻ-1 GIL was first displayed to the public, during an air show at Okęcie airfield (it was the first public presentation of a helicopter in Poland and one of first presentations in the Eastern Bloc). On 16 November 1953, the helicopter was damaged when the main rotor was bent by the wind and cut off the rear pylon, thus ending the test program. By then, the prototype had completed 169 flights, 20 hours 21 minutes in total.
In 1956, the helicopter was repaired and used for training flights by helicopter pilots. On 28 June 1957 a tail rotor gear (originally from a motorcycle) broke and it could not be replaced, consequently, the helicopter never flew again, being written off on 28 October 1960. During 1956–1957 it had completed 185 flights, for a total of 12.5 hours.
Data from 
- Crew: 1, pilot
- Capacity: 1
- Length: 8.5 m (27 ft, 10 in)
- Rotor diameter: 8.8 m (28 ft, 10 in)
- Height: 3 m (9 ft, 9 in)
- Disc area: 60.8 m2 (199 ft2)
- Empty weight: 510 kg (1,124 lbs)
- Loaded weight: 610 kg (1,344 lbs)
- Powerplant: 1 × Hirth HM 504 4-cylinder inline engine, fitted vertically, air-cooled, 105 hp (78)
- Maximum speed: 140 km/h (87 mph)
- Service ceiling: 2,000 m (5,560 ft)
- Rate of climb: 4.5 m/s (886 ft/min)
- Related development
- Aircraft of comparable role, configuration and era
- Glass 2005, pp. 44–45.
- Żurakowski 2005, pp.45–49.
- Witkowski 2005, pp. 49–51.
- "Polish Aviation Museum Cracow:Helicopter: SP-GIL". Retrieved 2010-06-25. backup: http://www.webcitation.org/5qkS6urcH
- Glass, Andrzej. "Śmigłowiec BŻ-1 GIL" (Polish). Lotnictwo, 2(47)/2005. ISSN 1732-5323.
- Green, William and Gerald Pollinger. The Observer's Book of Aircraft, 1958 edition. London: Fredrick Warne & Co. Ltd., 1958.
- Lambermont, Paul. Helicopters and Autogyros of the World. London: Cassell, 1958.
- Witkowski, Ryszard. "Powrót GILa i jego dalsze losy"(Polish). Lotnictwo, 2(47)/2005. ISSN 1732-5323.
- Żurakowski, Bronisław. "SP-GIL - wspomnienia konstruktora" (Polish). Lotnictwo, 2(47)/2005. ISSN 1732-5323.
|Wikimedia Commons has media related to BŻ-1 GIL.|