Enstrom 480

The Enstrom 480 is a light single-turbine helicopter produced by the Enstrom Helicopter Corporation in the United States. Designed for training, surveillance and light utility transport, it was certified in November 1993 and derives from the TH-28 military prototype. It is distinguished by the absence of a hydraulic system and by a pilot's station on the left, an unusual arrangement for a helicopter.

Development

In the 1980s, Enstrom produced two helicopters with horizontally opposed piston engines. When the US Army issued its NTH (new training helicopter) requirement for a turbine-powered trainer, the company developed an enlarged, turbine-powered version of the 280 Shark, designated TH28. The TH-28, based on the 280FX with a turbine engine, a widened cabin and enlarged horizontal and vertical tail surfaces, was certified in September 1992; six were built. The Army contract was not won, but management went ahead with a commercial version introduced in 1993, powered by the C20W variant of the Rolls-Royce Model 250 turboshaft. The 480B, with increased maximum weight and power limits, was certified in the United States in February 2001 and in Canada in February 2019.

Design

The fuselage is based on a welded steel tube structure, with aluminium skin and tail boom. The aircraft has no hydraulic system; a trim system absorbs rotor feedback and allows the pilot to hold the desired stick position. On the 480B, the turbine can deliver 420 shp but is limited to 305 shp for 5 minutes and 277 shp continuously, power available up to 13,000 ft MSL in a standard atmosphere, which preserves performance at high temperature or altitude. The engine drives a three-blade main rotor of 32 ft (9.75 m) diameter and a 5 ft tail rotor. Main rotor and hubs total 300 lb, providing substantial inertia in the event of a power loss. The 480 carries a pilot and four passengers, for an empty weight of 1,675 lb and a maximum weight of 2,850 lb; the 480B raises the latter to 3,000 lb, roughly 150 lb of additional payload. Cruising speed reaches 131 mph (211 km/h), range 435 mi (700 km), service ceiling 13,000 ft and rate of climb 1,500 ft/min.

Operational History

The type is widely used by small commercial operators and flight schools, most operating one or two aircraft. Military and government users include the Flight Training Center at Pardubice (Czech Republic), the armed forces of Equatorial Guinea, the Indonesian National Police, the Japan Ground Self-Defense Force, the Royal Thai Army, Venezuelan military aviation and the Zambian Air Force, which operates two. The York Regional Police (Canada) operated one example from 2000 to 2002, withdrawn because of excessive noise levels; Estonia used it within the Police and Border Guard aviation group.

Variants

• TH-28: military training and light patrol version derived from the 280FX, certified in September 1992, six built.
• 480: five-seat civil version derived from the TH-28, certified in November 1993.
• 480B: improved version with maximum weight raised to 3,000 lb and higher power limits.
• 480B Guardian: 480B configured for police missions, fitted with a nose-mounted camera and a searchlight.