Borgward Kolibri

BFK-1 Kolibri
Model of the Borgward-Focke BFK-1 Kolibri at the Bückeburg Helicopter Museum
General information
Type	Utility helicopter
National origin	German
Manufacturer	Borgward
History
First flight	8 July 1958

The Borgward BFK-1 Kolibri, or Borgward-Focke BFK-1 Kolibri, (Kolibri meaning "hummingbird" in German) was a German three-seated utility helicopter built by Borgward, designed by Heinrich Focke and was the first German helicopter after World War II. ^[1] The helicopter first flew on 8 July 1958 in Bremen, piloted by Ewald Rohlfs. ^[2]

Design and development

Two prototypes were built; they had steel tubing fuselages, covered with metal and fabric and v-tails with tail rotors at their tips. The plywood covered main rotors had three blades with steel tubing spars. The helicopter had a six-cylinder air-cooled Lycoming VO-435-A1B engine, producing 260 hp. ^[3] The fuel tank was capable of holding 180L. The helicopter could be used for spraying in agriculture, and could carry up to 300 lbs. Development ended after the two prototypes, as Borgward went bankrupt shortly after in 1961. ^[4]

Specifications

Data fromJane's All the World's Aircraft 1960-61 ^[5]

General characteristics

• Crew: 1
• Capacity: 2 passengers
• Length: 8.3 m (27 ft 3 in) fuselage
• Height: 3.05 m (10 ft 0 in)
• Empty weight: 800 kg (1,764 lb)
• Max takeoff weight: 1,200 kg (2,646 lb)
• Fuel capacity: 180 L (47.6 US gal; 39.6 imp gal)
• Powerplant: 1 × Lycoming VO-435-A1B air-cooled six-cylinder, 190 kW (260 hp)
• Main rotor diameter: 9.4 m (30 ft 10 in)
• Main rotor area: 4.3 m² (46 sq ft)

Performance

• Maximum speed: 160 km/h (99 mph, 86 kn)
• Cruise speed: 140 km/h (87 mph, 76 kn)
• Range: 320 km (200 mi, 170 nmi)
• Endurance: 3 hours
• Service ceiling: 4,500 m (14,800 ft) (absolute)
• Hover ceiling OGE: 600 m (2,000 ft)
• Rate of climb: 4 m/s (790 ft/min) (inclined) at sea level

1 m/s (3.3 ft/s) (vertical) at sea level

Notes

1. Aeroplane and Commercial Aviation News. 99: xlix. 1960.{{cite journal}}: Missing or empty |title= (help)
2. Lambermont, Paul Marcel; Anthony Pirie (1970). Helicopters and autogyros of the world. Barnes.
3. Royal Aero Club of the United Kingdom, United Service and Royal Aero Club (1959). Flight International. 75. IPC Transport Press Ltd.: 685.{{cite journal}}: Missing or empty |title= (help)
4. Aviation Week & Space Technology. 74. McGraw-Hill: 32. 1961.{{cite journal}}: Missing or empty |title= (help)
5. Taylor, John W.R., ed. (1960). Jane's All the World's Aircraft 1960-61. London: Sampson Low, Marston & Co. p. 159.

References

• Green, William (1961). The Observer's World Aircraft Directory. F. Warne. p. 142.