Sikorsky Aircraft introduced its electric Firefly at AirVenture 2010 this week, but other ways to achieve green aviation are also showing up at Oshkosh. Avimech International Aircraft introduced its Dragonfly tip-jet helicopter, powered by hydrogen peroxide. Besides turning brunettes into blondes, H2O2 has propulsive qualities, often functioning as part of a rocket fuel mix.
Manufacturing cargo conversion systems for large passenger aircraft and providing aircraft support services, Tuscon, Arizona-based Avimech promotes the use of H2O2 as a green fuel, and the new helicopter as an example of “Environmentally Responsible Aviation.”
Its simplicity is a major feature. Tip jet propulsion forces fuel from the tanks flanking the pilot through rotor-tip openings, where the fuel reacts with a catalyst, spinning the rotor and providing lift. Avimech claims that this simplifies operation and control of the small (220 pounds empty weight) chopper. Because there is no rotational torque, lift and autorotation supplied through “purely aerodynamic forces”, the pilot doesn’t have to use rudder pedals. With no engine, gar box, rudder pedals, or hydraulics, maintenance is simplified. Avimech notes that tail rotor is not needed, but retained on this design for hovering maneuverability.
The Dragonfly is reported to produce lower noise and less vibration than conventional helicopters, provide enhanced stability, and to be able to operate “in strong winds (such as landing on ships for emergency rescue).” Its claimed ability to lift an 800-pound payload seems to put it at some extreme of load-carrying efficiency.
“The only propulsion maintenance required is to flush the Tip-Jet system with water approximately every 20 hrs of operation. The H2O2 engines have a lifetime warranty,” Avimech adds. With 70-percent concentrated hydrogen peroxide costing $4.00 per gallon, customers can reduce operating costs by manufacturing their own, according to the manufacturer. The DF1 consumes about 11-12 gallons per hour, according to Aero-news.net.
Avimech sets the price at $120,000 for the FAA-certified Dragonfly; buyers at Oshkosh can get a special price during the show.