In 1981, Bell won a U.S. Army competition for a new scout helicopter. The design featured a four-bladed semi-rigid rotor system and an upgraded Bell 206L drivetrain. It proved to be much faster and with much less vibration than the 206L series from which it was derived. It also allowed a significant increase in takeoff gross weight. The U.S. Army refers to this model as the OH 58D and Bell’s designation is the Bell 406.
When customer demand indicated a need for a faster, more comfortable seven-seat light single-engine helicopter, it was logical to base the new design on the 406 dynamic systems.
Design of the new model, called the Bell 407, was launched in 1993 and focused on using a wider version of the proven Bell 206L4 airframe mated to the 406 dynamic systems. The result represents a major improvement over the 206L series of aircraft in every way.
The Bell 407 uses an all-composite four-bladed semi-rigid rotor and hub. The transmission uses a soft-mounted pylon isolation system to reduce vibration. The engine used on the Bell 407 is the Rolls-Royce 250-C47 with a single-channel FADEC system. A two-bladed tail rotor provides directional control. The fuselage is the same as the Bell 206L4 fuselage except that it has been widened by 7 inches and the windows have been enlarged. The fuselage is made of conventional aluminum alloy but the tail boom is constructed of composites. The cabin has two seats in front and an aft cabin with two seats facing aft and a three-seat bench facing forward. The cabin is long enough to allow carrying of two stretchers, one on top of the other, on one side of the cabin. This leaves room for two medical attendants. As with the Bell 206L, a skid landing gear is used for the sake of simplicity.
Certification of the Bell 407 to the standards of FAR 27 was obtained in early 1996 and deliveries started the same year. Since then, IFR certification was also obtained. Production takes place at Bell’s facility in Montreal, Canada.
Eagle Copters took the 407 and retrofitted it with a Honeywell HST900D-2 engine. This gives the 407 better fuel efficiency as well as better hot and high performance.