Dynamic Airline Centric Inbound Priority Sequencing

Abstract

During arrival waves at hub airports the surrounding airspaces can be congested, resulting in flight delays. To solve this congestion problem one of the current solutions is to sequence flights whilst they are still en-route by using an Extended Arrival Manager (E-AMAN). This paper aims at improving this E-AMAN concept by tackling two of its limitations. The first one is that priorities are not considered when sequencing the flights, as sequences are currently defined according to the First-Come-First-Served (FCFS) principle. The second limitation is that it is difficult to sequence so-called popup flights when creating the arrival sequence. These popup flights are defined as flights that have a departure airport that lies within the en-route horizon of the E-AMAN. The first limitation is tackled by proposing a dynamic Inbound Priority Sequencing (IPS) model for the use of a network carrier at their hub airport. The model sequences air traffic en-route in favor of the network carrier, by trading off the (potential delay) costs of individual flights. Each flight then receives a Target Time Over their Initial Approach Fix (TTO IAF). At the same time competitive traffic is not negatively influenced. The other limitation of E-AMAN is tackled by giving popup flights from small regional airports a so-called Company Calculated Take-Off Time (CCTOT) next to a TTO IAF, which is used to delay those flights whilst still on the ground. By the time flights enter the arrival Air Traffic Control (ATC) centers, the FCFS is applied up until landing, meaning ATC does not have to change their working principles. The objective of the IPS model is to minimize the overall arrival cost for the network carrier, consisting of optimizing for fuel cost, passenger missed connection cost, and Loss of Future Value cost. The model is formulated as a mixed-integer quasi-linear program. A novelty of the model, in addition to specifically including popup flights, is the fact that the sequence is recalculated each time new information is available. This information can be a new flight entering the action horizon of the model or a new Estimated Off Block Time for a departing flight at the hub to which passengers of an arriving flight have to connect to. At the same time the stability of the sequence is kept in mind by including a cost penalty for adjusting the TTO IAF. Results of a case study performed at Amsterdam Airport Schiphol for a Dutch network carrier show cost savings of 12\% compared to the traditional FCFS without en-route sequencing in a simulation environment. During validation of the model, by means of performing shadow runs using real-time flight data, it turned out the model can indeed be of help to reduce costs for a network carrier.