Influence of Aircraft Maneuver Preference Variability on Airspace Usage

Human factors constitute a core aspect of air traffic control concepts and must be addressed when dealing with traffic flow stability problems. This paper aims to evaluate how the usage of airspace depends on the degree of flexibility in pilot decision-making. Specifically, we study the airspace usage of two intersecting flows of aircraft when pilot maneuver preferences vary. The amount of airspace required for the two flows to cross without conflict can reveal certain aspects of traffic complexity of this specific traffic pattern. To simplify the analysis, we use models of instantaneous lateral and longitudinal position changes to approximate the heading-change and speed-change maneuvers of the aircraft, respectively. Pilot preferences, which are expressed as preferred heading or speed changes, are reflected by different penalty functions of position displacements that the pilots attempt to minimize during conflict resolution. Under the same pilot preferences, the aircraft flow stability is preserved using a decentralized conflict-resolution scheme. However, when the pilot preferences are allowed to vary so that individual aircraft have more control freedom in conflict resolution, the intersecting flows require a much larger fraction of airspace to ensure conflict-free and stable flows of aircraft.