Multi-Aircraft Dynamic Continuous Descent Approach Methodology for Low-Noise and Emission Guidance

Continuous descent approaches can significantly reduce fuel burn and noise impact by keeping arriving aircraft at their cruise altitude for longer and then having a continuous descent at near-idle thrust with no level-flight segments. The continuous descent approach procedures are fixed routes that are vertically optimized. With the changing traffic conditions and variable noise-abatement rules, the benefits of continuous descent approach are not yet fully realized. In this paper, a methodology is proposed to generate aircraft-specific dynamic continuous descent approach routes that are both laterally and vertically optimized for noise, emission, and fuel. The methodology involves discretizing the terminal airspace into concentric cylinders with artificial waypoints and uses enumeration and elimination (based on aircraft performance envelope) from one waypoint to another to identify all the possible routes. From the resulting set of possible continuous descent approach routes, routes are identified that represent the best tradeoff on the given objectives. The dynamic continuous descent approach algorithm is implemented in an air traffic simulator for the Sydney, Australia, terminal area. Dynamic continuous descent approach, as compared with a typical continuous descent approach, shows a 14.96% reduction in noise, 11.6% reduction in NOx emission, and 1.5% reduction in fuel burn. The throughput capacity of transition airspace is also investigated for multiple flights performing continuous descent approach operation for different traffic distributions. The methodology incorporates a delay algorithm that uses the flight's estimated time of arrival at the intermediate approach fix, which allocates a conflict-free continuous descent approach route by searching through possible routes.