Today, challenges in aviation are often related to the efficient handling of aircraft movements and airport operations in periods with high traffic volumes. During the last decade, airports have developed from simple infrastructure providers to high-performance companies. High quality of punctual and on-time flights has become a central element in goal definitions of airport operators. Further increase in performance, however, will be necessary to manage the predicted growth of passengers and flights. Using a simulation of the European aviation system, the effect of increased capacity at a local airport on the overall network performance is investigated using different scenarios. The results show significant potential to improve the network performance by enhancing a congested airport. A 5% capacity improvement at London Heathrow leads to 22% less inbound and 49% less outbound delay at the local airport. Nearly the same absolute amount of inbound delay can be saved at the other network airports due to benefit propagation effects. Further, the additional waiting time to use the runway decreases, and the punctuality of flights is improved.