In the mid-1980s, with the success of the R22 assured, Robinson Helicopter turned its attention to the four-seat piston helicopter market. At the time, there were no four-seat piston helicopters and the market potential seemed substantial. As with the R22, simplicity and low cost were the focus of this design. In 1990, the first flight of the prototype took place and certification of the R44 Astro was completed by the end of 1992. For a number of years after the R44 was certificated, it was not sold in the U.S. because of concerns over the cost of insurance and liability lawsuits. However, that restriction was lifted after approximately two years and this helicopter is now sold around the world.
One of the unique features of both the R22 and R44 is that all components that require overhaul and replacement come due at the same time (either 2,000 or 2,200 hours, depending on the model). Until 2000, the only way to get these components overhauled or replaced was to return the helicopter to the factory, where the entire helicopter was remanufactured for a fixed price. In 2000, Robinson also made a kit available that allows qualified organizations to perform the overhaul.
The Robinson R44 Astro is a light single-engine piston helicopter with a two-bladed semi-articulated main rotor. It uses a Lycoming O-540 engine. A two-bladed tail rotor provides directional control. All rotor blades are made of aluminum, as is the fuselage structure. The cabin has room for a pilot plus one passenger in front, and two passenger seats in back. A number of specially equipped models are available. One is the R44 Clipper, which is an R44 with fixed floats. Other models are specially equipped for police and news gathering. The fuselage is mounted on a skid gear.
Development of the R44 was launched in 1986, certification of the R44 Astro to FAR 27 standards was obtained at the end of 1992 and first deliveries followed immediately thereafter.
The R44 Cadet is the utility version of the R44 Raven I. Everything is the same except maximum gross weight is 200 pounds less, the rear seats have been removed and the area has been reconfigured for cargo. The Lycoming O-540-F1B5 engine power has been de-rated to 210 hp takeoff/185 hp continuous. This is slightly lower than the Raven I’s 225/205 hp. The lower gross weight and de-rated engine power give the Cadet slightly better hot and high performance. A newly designed muffler also makes the Cadet quieter than its predecessor.
The overhaul interval for the airframe and engine has been raised by 200 hours, making maintenance operating costs slightly less than the Raven I.