The Bell 206 is a family of two-bladed, single- or twin-engine helicopters, manufactured by Bell Helicopter at its Mirabel, Quebec plant. Originally developed as the Bell YOH-4 for the United States Army's Light Observation Helicopter program, the 206 failed to be selected. Bell redesigned the airframe and successfully marketed the aircraft commercially as the five-place Bell 206A JetRanger. The new design was eventually selected by the Army as the OH-58 Kiowa. Bell also developed a seven-place LongRanger, which was later offered with a twin-engine option as the TwinRanger, while Tridair Helicopters offers a similar conversion of the LongRanger called the Gemini ST. The ICAO-assigned model designation "B06" is used on flight plans for the JetRanger and LongRanger, and the designation "B06T" is used for the twin-engine TwinRangers.
On October 14, 1960, the United States Navy solicited response from 25 aircraft manufacturers to a request for proposals (RFP) on behalf of the Army for the Light Observation Helicopter (LOH). Bell entered the competition along with 12 other manufacturers, including Hiller Aircraft and Hughes Tool Co., Aircraft Division. Bell submitted the D-250 design, which would be designated as the YHO-4. On May 19, 1961, Bell and Hiller were announced as winners of the design competition. Bell developed the D-250 design into the Bell 206 aircraft, redesignated as YOH-4A in 1962, and produced five prototype aircraft for the Army's test and evaluation phase. The first prototype flew on December 8, 1962. The YOH-4A also became known as the Ugly Duckling in comparison to the other contending aircraft. Following a flyoff of the Bell, Hughes and Fairchild-Hiller prototypes, the Hughes OH-6 was selected in May 1965.
When the YOH-4A was eliminated by the Army, Bell went about solving the problem of marketing the aircraft. In addition to the image problem, the helicopter lacked cargo space and only provided cramped quarters for the planned three passengers in the back. The solution was a fuselage redesigned to be more sleek and aestheticly appealing, adding 16 cubic feet (0.45 m3) of cargo space in the process. The redesigned aircraft was designated as the Bell 206A, and Bell President Edwin J. Ducayet named it the JetRanger denoting an evolution from the popular Model 47J Ranger.
Crew: 1 pilot
Capacity: 4 passengers
Length: 39 ft 8 in (12.11 m)
Rotor diameter: 33 ft 4 in (10.16 m)
Height: 9 ft 4 in (2.83 m)
Disc area: 872 ft² (81.1 m²)
Empty weight: 1,713 lb (777 kg)
Max. takeoff weight: 3,200 lb (1,451 kg)
Powerplant: 1 × Allison 250-C20J turboshaft, 420 shp (310 kW)
Maximum speed: 130 knots (224 km/h, 139 mph)
Range: 374 nmi (430 mi, 693 km)
Service ceiling: 13,500 ft (4,115 m)
Rate of climb: 1,350 ft/min (6.9 m/s)
Disc loading: 4 lb/ft² (177 N/m²)
Power/mass: 0.26 hp/lb (420 W/kg)