Balancing Air Traffic Control workload across dual area navigation arrival procedures

Area navigation (RNAV) is a key component for improving the efficiency and capacity of the National Airspace System (NAS). As such, the Federal Aviation Administration (FAA) has been implementing RNAV standard instrument departures (SIDs) and standard terminal arrival routes (STARs) at airports throughout the NAS. An increasingly more common aspect of the implementation process involves a Human-in-the-Loop (HITL) simulation of new procedure designs in the pre-implementation phase to evaluate traffic management difficulty, given the proposed changes, and to validate operational assumptions. The terminal area route generation evaluation and Traffic Simulation (TARGETS) tool, developed by the MITRE Corporation's Center for Advanced Aviation System Development (CAASD), provides a testing platform to simulate traffic in both en route and terminal airspace in an integrated operations setting to achieve an accurate representation of site-specific air traffic environments. This paper describes the simulation results of a large airport environment where dual RNAV STAR procedure designs were evaluated by conducting a HITL simulation using the TARGETS tool with certified professional controller (CPC) participants. The dual RNAV STARs are created as parallel arrival routings, designed with sufficient separation between them to allow for independent operations, and are used to manage high arrival demand or mixed aircraft performance over a given corner-post. During this simulation, aircraft on these STARs needed to be efficiently merged within terminal airspace, where space for vectoring was limited, in order to feed a single runway. The focus of the simulation was to assess how different traffic delivery strategies, referred to as the dasiaoperational usepsila of the RNAV STARs, could be used to move traffic from en route to terminal radar approach control (TRACON) airspace and the associated impacts on Air Traffic Control (ATC) workload. Other data included track data and participant feedback captured in a focus group-like discussion conducted at the conclusion of each scenario. Results show that when traffic was equally distributed across the parallel RNAV procedures, workload increased for TRACON controllers. In contrast, when traffic was primarily delivered using a single RNAV procedure, workload increased for the Air Route Traffic Control Center (ARTCC) controllers. A solution that provided more of a workload balance was achieved by allowing ARTCC controllers to offload aircraft on the first RNAV procedure (primary flow) to the second RNAV procedure (secondary flow), on an as-needed basis. The results of this effort reflect the effectiveness of HITL simulation in the pre-implementation phase for identifying tailored air traffic management solutions that can help increase the likelihood of successful RNAV procedure implementation so that benefits can be enabled.