Currently, many Chinese airports have an unreasonable distribution of flight schedules, and the capacity of runways or corridors is often not met, which leads to delays. With the rapid growth of airports in recent years, it has gradually become the norm that multiple adjacent airports share the same corridor. It means that it's possible to redistribute the corridor capacity in the neighboring airport cluster. This paper proposes a single-airport flight slot optimization model that considers the public corridor of multiple adjacent airports and reduces unnecessary flight delays by allocating adjacent airports' remaining capacity to the target airport. The model's objective function minimizes the volume of adjusted flights on the premise of meeting the capacity constraints to reduce the cost of optimization while reducing delays. We apply this model to Tianjin Binhai International Airport and its neighboring airports. Simulation experiments show that this method can improve the feasibility of optimization and effectively reduce delays.

CICTP