Bell 207 Sioux Scout
Bell proposed the Iroquois Warrior for an interim programme which later became known as AAFSS or Army's Advanced Aerial Fire Support System and, by December 1962, also modified an OH-13S as an armed helicopter which would combine the desired combat potential with the desired flight performance. The aircraft, known by Bell as Model 207 Sioux Scout embodied a low drag profile, crew of two seated in tandem with integrated weapons, sighting systems and equipment. A new profiled fuselage was made from a Model 47J-2 rear fuselage mated with an all-new glazed streamlined cockpit with reinforced plastic bubble. The landing gear was of the skid-type. As powerplant the Sioux Scout retained the 260hp turbo-supercharged Lycoming TVO-435-A1A and had the rotor system of the OH-13S. The crew was seated in tandem with dual flying controls. The pilot was above and behind the gunner who controlled an Emerson Electric TAT-101 chin-turret armed with two 7.62mm machine-guns. This turret was a privately-funded modified version of the M-60-C gun barbette which, linked to the movement of the gunner's sight, could swivel 200deg in azimuth, and 15deg above and 45deg below the horizon. The Sioux Scout also incorporated stub wings which had been designed to carry auxiliary fuel tanks as well as providing extra lift. Flight tests showed that these wings also improved high-speed turning capability. Several types of wings were evaluated on the Model 207, as well as various types of cowlings, tailboom elevators and fins.
The sole Model 207 prototype (N73927) made its maiden flight on 27 June, 1963, with Al Averill at the controls. This flight lasted ten minutes and by 25 July, the Sioux Scout had logged 18hr 30min flying. At the end of 1963, the aircraft was passed to the US Army for further evaluation by pilots of the 11th Air Assault Division at Fort Benning in Georgia. The Army pilots were surprised at the Model 207's capabilities and asked that such an aircraft but with a more powerful engine be promptly developed.
In fact, albeit a highly promising concept, the Sioux Scout was somewhat limited in true combat capability and had no future. Only the one was built.
Bell 207 "Sioux Scout"
Engine: 1 x Lycoming TVO-435-A1A turboshaft, 194-kW (260-hp)
Main rotor diameter: 11.28m