Three-Degree Decelerating Approaches in High-Density Arrival Streams

Trajectory unpredictability of aircraft performing continuous descent approaches results in reduced runway capacity, because more spacing is applied. A possible solution to this problem is self-spacing: the transfer of the spacing task from the controller to the pilot. Using a fast-time simulation tool, the performance differences between distance- and time-based self-spacing in high-density traffic in terms of runway capacity and separation are quantified for the three-degree decelerating approach. Distance-based self-spacing is the most promising concept. The average runway capacity is 39 aircraft per hour (40% heavy, 60% medium aircraft). Runway capacity in the case of time-based self-spacing is 3 aircraft per hour lower, due to spacing margins applied to lower the separation violation rate to the level of distance-based spacing. A sensitivity analysis was carried out for distance-based self-spacing. One of the results is that accurately determining the starting time and subsequently arriving at this time benefits the three-degree decelerating approach performance. Three-degree decelerating approach performance is also affected by the initial speed and altitude, as they affect the three-degree decelerating approach's control space. [PUBLICATION ABSTRACT]