Going Green: What's in it for General Aviation?

Global warming concerns have prompted actions to restrict carbon dioxide emissions by a rapidly growing number of nations throughout the world. The aviation community can expect emission limits in the near future, and should become pro-active in this arena. Rapid advances are being made in the automobile industry to research and develop more efficient vehicles. The very successful introduction of gasoline-electric hybrid automobiles has spawned intense research and development of advanced batteries, ultra-capacitors, electric motors and controls. Opportunities for adapting automobile technologies to small general aviation airplanes should be exploited. Over the past few years, several groups have successfully flown experimental airplanes powered by ground-rechargeable batteries. Performance studies of small single-engine battery-powered airplanes show that performance is severely restricted because of low specific energy values (kWh/kg) of chemical batteries compared to traditional fossil fuels. However, advantages of zero in-flight emissions, high reliability, and fuel cost of only $1/gallon of avgas equivalent make the battery-powered airplane increasingly attractive. An airplane with minimum power lift-to-drag ratio (L/D) of 17 and battery with specific energy of 0.250 kWh/kg will provide single-person flight duration of two hours, or two-person flight duration of one hour, adequate for many Light Sport Aircraft (LSA) and training operations.