The Sun Flyer, which is to be FAR 23 certified, is powered by an electric propulsion system. Lithium Ion batteries run the electric propulsion system, which directly drives the composite propeller. Engine performance is controlled by an electronic control unit which ensures optimal use of the energy stored in the batteries. The electric design features reduced cooling drag compared to a conventionally powered aircraft and nose frontal area is reduced due to a smaller motor size and cooling intake required. Propeller efficiency is improved due to the utilization of additional blade area when contrasted to an internal combustion engine aircraft.
The Sun Flyer electric power is completely emission free. No avgas with CO2 in the exhaust. Furthermore, noise associated with the operation of the aircraft is a very quiet 55dB, allowing the use of airports near populated areas without local residents being disturbed by excessive noise.
The electric motor's throttle is very intuitive with one control lever. There is no need to adjust mixture richness and monitor cylinder head temperature as in aircraft with internal combustion engines. The throttle computer control unit is responsible for optimum motor operation, battery status and the entire power system all necessary information is shown on digital display.
The operating costs of the Sun Flyer are five times lower than the costs associated with similar training airplanes equipped with fuel burning internal combustion engines. Only about $3 of electricity is needed for each flying hour.