Taxiing under jet power is not the most efficient, or environmental, way to get around and electrically powered nose wheels
are under development to reduce fuel consumption and emissions during ground operations. Now the German Aerospace Center (DLR) is taking the next step - powering the nose wheels from a clean and quiet fuel cell
Tests of the fuel cell-powered electric nose-wheel drive system are planned for April in Hamburg, using DLR's Airbus A320 Advanced Technology Research Aircraft (ATRA). The drive system comprises two electric motors built into the nose wheels, driven by four aircraft-grade 12.5kW proton exchange membrane (PEM) fuel cells.
DLR says the fuel-cell system is capable of powering the nose wheels of an aircraft weighing up to 70 tons (the maximum ramp weight of an A320 is 74-78 tons). Fuel-cell power will reduce emissions by up to 27% and noise by up to 100% compared with ground operations under jet engine power, saving 200-400 liters of fuel a day based on seven take offs and landings a day, DLR calculates.
Tests of the electric nose wheels are the third phase of DLR's ELBASYS (electric baseline systems) research project, which aims to demonstrate a zero-emissions replacement for the conventional gas-turbine auxiliary power unit (APU) and emergency power sources such as the ram-air turbine.
In the first phase of the project, working with Airbus and Michelin, DLR integrated a 20kW fuel-cell system into the ATRA to provide emergency power to the electric motor pump on the back-up hydraulic system and ailerons. Flight tests were conducted in 2007-8.
In the second phase, the fuel cell also produced water for the toilets and air-conditioning system and low-oxygen air to inert the fuel tanks. This multi-function capability is aimed at offsetting the weight penalty of the fuel-cell power system compared with an APU.