Data-Driven Analysis of Inefficient Arrival Separation

Maintaining flight separation is key to ensuring safety in aircraft arrival operations. While sufficient separation is required for flight safety, excessive separation during peak hours can lead to reduced air traffic system capacity, extra arrival delay, and undesirable fuel burn. To maintain flight safety and accommodate high traffic volume, traffic flow guidance strategies (TFGS) are deployed to adjust flight landing time through extra flight distance. Previous studies have established the key factors affecting the separation deviation. However, gaps still exist in identifying inefficient separation, which can be mitigated by altering the air traffic management strategy. In this study, we extract flight trajectory features such as flight separation, standard arrival routes, and TFGS from ADS-B flight trajectory data. Through these features, we establish the effect of TFGS on arrival flight separation deviation. We characterize inefficient arrival separation through trajectory features, separation deviation, and traffic dynamics. We also quantify the back propagation effect of the inefficient separation, in which the negative impact is not limited to a single flight. Our investigation based on air traffic data pertaining to the Hong Kong International Airport reveals that a notable portion of arrival flights have elements of inefficient separation; hence, there is room for improvement. The associated back propagation effect is also prominent. It can affect up to 20% of the daily arrival flights, and on average increase their time spent in terminal maneuver area by 15%. Our study provides an atomic evaluation on arrival separation that can serve as a guide to improve air traffic management operations.