One 195kW (260hp) Textron Lycoming O-540 flat six piston engine derated to 165kW (225hp) for takeoff and 153kW (205hp) for continuous operation driving a two blade main rotor and two blade tail rotor.
Cruising speed at 75% power 209km/h (113kt). Initial rate of climb 1000ft/min. Service ceiling 14,000ft. Hovering ceiling in ground effect 6400ft, out of ground effect 5100ft. Max range with no reserves approx 645km (350nm).
Standard empty 635kg (1400lb), max takeoff 1090kg (2400lb).
Main rotor diameter 10.06m (33ft 0in), length overall rotors turning 11.76m (38ft 7in), height 3.28m (10ft 9in). Main rotor disc area 79.5m2 (855.3sq ft).
Typical seating for four, with two passengers on bench seat behind pilot and passenger.
By September 2000, 868 R-44s had been delivered since production began in late 1992.
Four place piston engined light helicopter
While bearing a resemblance to the earlier R-22, the piston engine powered four seat R-44 is much larger and is almost as long as the turbine powered Bell JetRanger.
The comparison with the JetRanger is useful as it provides a good illustration of Robinson's design philosophy in developing the R-44. The aim in developing the R-44 was to provide a relatively fast (205 to 215km/h [110 to 115kt] cruising speed) and useful four seat light helicopter that had performance close to that of turbine powered aircraft, yet with an acquisition cost of just a third of turbines and significantly lower maintenance costs.
Robinson Helicopter Company president and founder Frank Robinson first began design work on a light four seat piston engined helicopter during 1986. First flight occurred on March 31 1990 following extensive structural and dynamic component fatigue testing. US FAA certification was awarded on December 10 1992, with deliveries commencing soon after.
The R-44 proved to be very popular almost immediately and more than 860 have been built at Robinson's Torrance, California plant for customers worldwide.
The R-44 also uses the same simple design, construction and operating philosophies behind the design of the smaller two place R-22. A 194kW (260hp) Textron Lycoming O-540 flat six (derated to 165kW (225hp) for takeoff) drives two blade main and tail rotors, while other features include an electronic throttle governor, rotor brake and automatic clutch.
Apart from the standard R-44 Astro, the R-44 is also offered in float equipped R-44 Clipper form (certificated in July 1996); the R-44 Police law enforcement machine with IR sensor or television camera mounted in a gyrostabilised nose turret, video monitor, a searchlight and bulged door windows (certificated in July 1997); and the R-44 Newscopter which can carry a TV camera in a nose turret.
In April 2000, the R-44 Raven was introduced, which has adjustable pedals, elastomeric tail rotor bearings, and a hydraulic flight control system.