Tucked away in the quiet little airport at Hollister, California, ZeroAvia has stealthily been developing a hydrogen-powered Piper Malibu, and flying it for the last six months. It sounds like a regular aircraft taking off and passing overhead, even with its two 130 kilowatt (174.26 horsepower) electric motors. ZeroAvia claims 275 kW (369 hp) for the pair. From the videos, propeller noise seems to be much the same as a conventional, internal-combustion powered Malibu, but lacks the added noise of the engine. Piper M-series aircraft are normally powered by a Teledyne Continental Motors TSIO-520BE engine rated at 310 hp (230 kW). Valery Miftakhov, ZeroAvia’s founder and CEO announced, “Right now we have an aircraft that’s six seats and 2 tons …