Sonex Electric Sport Aircraft
The Sonex Electric Sport Aircraft (ESA) is a two-place (one place with additional batteries) aircraft design currently under development by Sonex Aircraft, using the Sonex e-Flight electric system for thrust. Sonex is designing this aircraft as a part of an attempt to develop alternate fuels, to ensure feasibility of inexpensive sport aviation in the future. Design and development. The ESA is designed to use the Sonex e-Flight electric system, which is concurrently under development. The airframe is developed from the Xenos, and is not intended to compete with the other aircraft in the  Sonex line. The initial flights, however, have used a Waiex airframe, and are centered around testing the electric power system. The aircraft will be aluminum riveted, and features will include a shortened wingspan and tail tips (in relation to the Xenos), aerobatic wing tips, 8' flaps instead of spoilers, and for the center of gravity, an auxiliary battery and controller in the tail cone. The electrical system will be 270 volts and 200 amps, and will be adjustable to different power outputs. As of 2007, the brushless DC-Cobalt motor was designed be very lightweight, at only , to operate at  90% efficiency, and to use Lithium-ion and Lithium-polymer batteries. For safety, the batteries are contained in "safety boxes", which are designed, in the event of a problem, to direct fire or explosion through designated holes, and to help cool the cells normally. In the final version, the batteries will be able to be charged in the aircraft, while retaining the ability to be easily removed and swapped with other batteries. The design won the Lindberg Electric Aircraft Prize for the "Best Electric Aircraft Sub-System or Component Technology" at Airventure 2010, and at that time the first completion  of a production aircraft was anticipated for the end of 2011.