The objective of this workshop was to identify prospective uses of fuel cells and perform an initial assessment of the fuel cells potential contribution regarding emissions reduction in the field of Aeronautics. Key questions such as what fuel cell is the most appropriate for use in aviation, what is its function and how should it be used, what fuel should we use and how will alternative fuels impact on this, what will the potential impact on airport air quality, where are the gaps in our knowledge relative to Ecats R&D in general, were addressed.