On November 4, 2010, George Bye of Bye Energy announced his plan to fly a 1978 Cessna 172, complete with an electric propulsion system sometime in the Spring of 2011.

This would be a significant first step toward developing an electric hybrid propulsion system. Mr. Bye said he will eventually use a jet-fuel-powered auxiliary power unit to recharge the flight craft’s batteries, thus extending the airplane’s range. He added that there is no need to test it on its maiden flight.

Photo of a Cessna 172 in flight

The airplane’s rear seats will be removed and replaced with lithium ion batteries. Bye reminded the press that already lithium ion batteries are already used commercially. Cessna, which is supporting Bye’s engineering, certified as standard a 44-amp lithium ion battery on the Citation CJ4, for starting and emergency backup. Cessna and A123 Systems developed the battery. They first used a Li-ion battery aboard a business jet. It weighs less than standard lead-acid batteries.

Bye stated that, in contrast to a fueled engine, electric motors are indifferent to changes in density altitude. They do not merely offer a clean alternative to fueled airplane engines. Electric motors maintain full power at altitude, he said.

Mr. Bye would not comment on whether his firm would manufacture conversion kits for Cessna 172s and said it is not yet able to determine a price for such a conversion.