Airport capacity is one of the most pressing issues facing European mobility today. As competing global hubs in the Middle East and other emerging economies power ahead with their own infrastructure roll-outs, European air traffic is set to be heavily congested in the coming decades. EUROCONTROL estimates that by 2040 up to 1.5 million flights will not be accommodated, meaning 160 million passengers unable to fly. Yet expansion of airport capacity in Europe faces a range of obstacles, from economic regulation and planning rules to political intervention and financing challenges. There is a need to both invest in new airport capacity and to make the best use of existing capacity. This should be achieved through integrated operations and collaborative decision-making, as well as through the airport slot allocation system. Airports need to see their capacity enhanced and allocated so as to develop air connectivity to the socio-economic benefit of the regions they serve, while limiting environmental impacts.