Jetcruzer International has placed a firm order for ZeroAvia's 600-kilowatt electric propulsion system to support development of its six-seat hydrogen-electric 500E airplane, the companies announced today. According to ZeroAvia, this is the first firm order for the ZA600, which the company has developed to convert aircraft carrying up to 20 passengers to hydrogen power. It has previously reported preorders for 2,000 units.