Nominal flight time optimization for arrival time scheduling through estimation/resolution of delay accumulation

In the arrival air traffic management, aircraft are provided with each one's scheduled time of arrival to satisfy the required time interval from the preceding one at a specific point, e.g. runway threshold, metering and merging points, etc. In general, the interval between aircraft in a traffic stream is controlled by delaying the following one, which inevitably results in delay accumulation and operational inefficiency. Because the scheduled time of arrival also depends on the nominal flight time toward specific points, it is considered possible to optimize the nominal flight time to minimize the operational cost of whole traffic stream. In this study, the nominal flight time optimization strategies through the estimation/resolution of the delay accumulation are proposed, and its feasibility is discussed. Through mathematical delay analyses, it is proven possible to estimate the delay accumulation by using the statistics of the traffic arriving at the initial point of the arrival scheduling. The feasibility to optimize the nominal flight time is then clearly demonstrated through the numerical traffic simulation. When the nominal flight time is longer than the minimum one, it is possible to reduce the flight time. When the traffic control with the flight time reduction is applied, it becomes possible to resolve the delay accumulation. It is further clarified that the optimum scheduled time of arrival can be directly estimated from the cost function of a single aircraft in the case of such a traffic free of delay accumulation. In addition, the maximum runway use and the equality of the operation performance are simultaneously achieved.