Safety Evaluation of Advanced Self-Separation Under Very High En Route Traffic Demand

Abstract

Since the “invention” of free flight, the key question is whether airborne self-separation can safely accommodate very high traffic demand. The aim of this paper is to answer this question for en route airspace. Therefore, an advanced airborne self-separation concept of operation is evaluated on safety risk at very high traffic demands. The advanced airborne self-separation concept of operations considered is of the trajectory-based operation type, in the sense that each aircraft manages a conflict-free four-dimensional trajectory intent and broadcasts this to the other aircraft. Complementary to this trajectory-based operation layer, each aircraft makes use of a short-term conflict detection and resolution layer that aims to resolve any remaining problems, such as significant deviations from four-dimensional intents due to wind prediction errors. Safety risk analysis is conducted using advanced techniques in agent-based modeling and rare-event Monte Carlo simulation. The results obtained show that the advanced self-separation concept of operations considered has a remarkably good collaboration between the trajectory-based operation and the tactical resolution layers: as a result of which, it can safely accommodate very high en route traffic demands.