At Europe's most congested airports demand for take‐off and landing slots has exceeded the available supply for many years. Yet, in the face of persistent growth in air traffic activities, these airports have achieved remarkable increases in their capacities to handle flights, despite retaining the same basic infrastructures. This paper investigates this growth of capacity as a ‘problem centred innovating system’, in which the roles of procedural change and co‐operation between teams are highlighted. ‘System evolution’ is also observed, as over time new agents with different knowledge bases have been brought into ‘the system’ to assist with the search for additional capacity.