A Belgian company called Sagita earned attention at this year's Paris Air Show with its Sherpa mockup, a two-seat, 575-pound helicopter turning counter-rotating blades driven by a compressor system. The compressor is driven by a 130-hp powerplant. It takes air in at the rear of the fuselage and then splits its output, sending some air back to the engine and the rest through the powerplant's cooling system.
After leaving the cooling system, that warmed air is then mixed with the engine's exhaust and sent to two turbines that directly drive each rotor. According to the company, the system is 85 percent efficient. And they've already set targets for production and price.The company hopes to fly the aircraft in two years and start delivering production models in three. It believes the offering will provide customers with a helicopter that is safer, simpler and easier to maintain than more traditional small piston-powered helicopters. Sagita says the Sherpa's transmission requires no lubrication or cooling. It believes that the Sherpa's simplicity and lower parts count will translate into cost savings and improved reliability for operators.In operation, the company projects the helicopter to be capable of carrying 287 pounds of useful load flying at an 85-knot cruise. Twenty-two gallons are expected to provide the aircraft with three hours endurance. Sagita has flown a 1/5 scale technology demonstrator and hopes to follow that with flights of a full-scale prototype sometime in 2015. If the aircraft makes it to market, Sagita says it is targeting a sale price near $200,000.Source: AVweb, Glenn Pew
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