[1] In 2013, the FAA National Kit Evaluation Team (NKET) approved fast-build "51% rule" versions of the Sonex, Waiex, and Onex.

The E-flight projects includes using an electric motor, ethanol-based fuels, and other power plant alternatives.

[10] In December 2010, an all-electric Waiex was test flown from Wittman field in Oshkosh, Wisconsin.

The aircraft was flown with a 54 kW (72 hp) brushless DC electric motor, managed by a newly designed controller.

Power is from a collection of 14.5 kW-hour lithium polymer batteries, giving the aircraft an endurance of one hour at low-speed cruise or 15 minutes of aerobatics.