In 1959, the Enstrom Helicopter Corporation was founded to design and sell small, reasonably priced helicopters. The first helicopter produced by Enstrom was the F-28A. This piston helicopter first flew in 1962 and deliveries started in 1968. In subsequent years, over 1,000 piston-powered Enstroms have been delivered. In the late 1980s, Enstrom redesigned the F-280 to incorporate a de-rated Rolls-Royce turbine engine and an enlarged cabin. This design was at least in part in response to an upcoming U.S. Army competition for a new turbine-training helicopter. The resulting helicopter was named the Model 480. The 480 was upgraded to the 480B in 2001. The upgrade included an increase in the transmission rating and an increase in the maximum takeoff gross weight.
The 480B is a light single-engine turbine helicopter. It is powered by one de-rated Rolls-Royce 250-C20W engine. The engine drives a three-bladed, fully articulated rotor unchanged from the F-280FX. A two-bladed tail rotor provides directional control. A unique feature of the dynamic system is that the rods that control main rotor blade pitch run inside the main rotor shaft. The swash plate that controls the blade pitch is mounted inside the aft fuselage. Power is transferred from the engine to the main transmission by a set of pulleys and V-belts. This arrangement also provides a clutch between the engine and the rotor. The main and tail rotor blades are made of aluminum, as is the fuselage. The cabin seats four or five in the high-density configuration, with one pilot and four passengers on two small benches, one behind the other. In the four-seat configuration, the passengers are seated on one seat next and forward of the pilot and with two on a bench behind the front-seat passengers. The fuselage rests on a fixed skid gear.
Design of the 480 was launched in early 1987. The first flight of the 480 occurred in 1988 and certification was obtained in 1993. Certification of the upgraded 480B was obtained early in 2001. Deliveries started the same year.