Airports are stable providers of infrastructure assets, even in the sometimes turbulent aviation industry. While airports and airlines are intrinsically linked and rely on one another to operate efficiently, they are based on different business models. Airlines are able to move quickly and respond to changes in traffic flows by leasing or retiring capacity. Airports, on the other hand, must make long-term planning decisions to safeguard capacity sometimes 50 years into the future. From user charges regulations to non aeronautical revenues, ACI offers different training programmes in this area to support its members.