The TSAT Allocation System at London Heathrow: The Relationship Between Slot Compliance, Throughput and Equity

London Heathrow is an extremely popular airport, where efficient take-off sequencing is important for ensuring a high runway throughput. Aircraft are usually released from the stands as soon as possible, providing the maximum pool of aircraft at the runway from which to choose from when sequencing. This paper considers the task of predicting the delay that aircraft will experience, so that some of it can be absorbed at the stand before the engines are started, reducing the fuel burn, with consequent environmental and economic benefits. Doing this requires determining the value of a take-off sequence, in order to identify good sequences. This paper considers the trade-off between three mutually conflicting objectives – minimising delay, complying with network departure constraints, and treating aircraft equitably and provides important insights for use in tuning the system to controller preferences. It also indicates potential benefits for controllers from the implementation of such a system.