Boeing FuelCell Airplane
Boeing completes systems integration testing of its fuel cell airplane, complete with lightweight batteries, and moves to conduct experimental flight tests this year. ...
... "The Boeing demonstrator uses a Proton Exchange Membrane (PEM) fuel cell / lithium-ion battery hybrid system to power an electric motor, which is coupled to a conventional propeller. The fuel cell provides all power for the cruise phase of flight. During takeoff and climb, the flight segment that requires the most power, the system draws on lightweight lithium-ion batteries. Flight tests, which will take place in Spain, will demonstrate for the first time that a manned airplane can maintain a straight level flight with fuel cells as the only power source. " ...
Via Boeing: Boeing Prepares Fuel Cell Demonstrator Airplane for Ground and Flight Testing