The electrification of aviation is a difficult challenge. The high weight of batteries, and the resulting short range and limited payload that results, have limited applications of electric drive to smaller, propeller-driven general aviation aircraft. But flight training, which typically uses smaller, short range piston powered aircraft, is ideal for electrification. Denver-based Bye Aerospace has created a purpose-built two-seat electric trainer called the eFlyer2, which is in the FAA certification process right now. Four flight training companies have ordered 340 aircraft, a production run that may nucleate the first sustained mass production of electric light aircraft in America.  * * * Want to watch this podcast as a video? This Week in Engineering is available on engineering.com TV along with all of our other shows such as End of the Line, Designing the Future, Manufacturing the Future, and the Engineering Roundtable.