Environmentalism Meets Aviation

Boeing researchers and their European industry partners are planning to conduct experimental test flights this year of a manned airplane powered only by a fuel cell and lightweight batteries. In an effort to develop environmentally progressive technologies for aerospace applications, the group will travel to Spain to conduct testing on systems that have been in development since 2003.

The integration phase of the Fuel Cell Demonstrator Airplane research project was completed recently. Thorough systems integration testing is now under way in preparation for upcoming ground and flight testing, according to Boeing.

"Given the efficiency and environmental benefits of emerging fuel cell technology, Boeing wants to be on the forefront of developing and applying it to aerospace products," said Francisco Escarti, BR&TE managing director, which is part of the Boeing Phantom Works advanced R&D unit. "The Fuel Cell Demonstrator Airplane project is an important step in that direction."

The goal of the test flights is to demonstrate for the first time that a manned airplane can maintain straight and level flight, with fuel cells as it's only power source.

A fuel cell is an electrochemical device that converts hydrogen directly into electricity and heat without combustion. Fuel cells are emission-free and quieter than hydrocarbon fuel-powered engines. They save fuel and are cleaner for the environment.

The aircraft being tested 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. During takeoff and climb, the flight segment that eats the most power, the system draws on lightweight lithium-ion batteries. While cruising, all power will be drawn from the fuel cell.

"While Boeing does not envision that fuel cells will provide primary power for future commercial passenger airplanes, demonstrations like this help pave the way for potentially using this technology in small manned and unmanned air vehicles," Escarti said. "It also gives us hands-on experience to complement other fuel-cell studies being carried out throughout the company."

There is definite promise in fuel cell technology as well as the PEM system. There is a Solid Oxide Fuel Cell that could be applied to secondary power-generating systems, such as auxiliary power units. Potential use in commercial aviation could be realized in 10 to 15 years.

The demonstrator aircraft is a Dimona motor glider, built by Austria's Diamond Aircraft Industries. The motor glider has a wing span of 53.5 feet (16.3 meters) and should cruise around 62 miles per hour on fuel cell power.

FMI: www.boeing.com