AircraftA collaboration of aircraft makers, fuel cell developers and university engineers have come a step closer to zero emission passenger flights with the first flight of a hydrogen fuel cell four-seater electric aircraft. The twin-cabin, (relatively) low-noise HY4 took off at 11:15 am (local) today for a quick zip around Stuttgart Airport. The HY4’s 21.36 m (70 ft) wing is home to the HY4’s central single propeller with a two-seater fuselage on either side, a…