FIELD TEST EVALUATION OF THE CTAS CONFLICT PREDICTION AND TRIAL PLANNING CAPABILITY B. D. McNally, R. E. Bach, and W. Chan Abstract The conflict prediction and resolution capability resident in the Center/TRACON Automation System (CTAS) has been enhanced and field tested. All-track processing (overflights, arrivals, departures), conflict probability estimation, and interactive trial planning, were incorporated into the Conflict Prediction and Trial Planning (CPTP) tool for field test evaluation. The objective of the work was to field test CPTP under operational air traffic control conditions and to measure benefits of CPTP capability to air traffic controllers and airspace users. The system was tested on the operational floor at the Denver Air Route Traffic Control Center in September 1997. It was found that controllers using CPTP-aiding resolved many conflicts by issuing a direct-route clearance to one of the aircraft. A direct route often resolved a conflict well before it became tactical, gave the aircraft a short-cut, and required one less controller clearance. The potential for a three-fold increase in direct routing was noted with CPTP-aiding over baseline operations with no aiding. The data show better than a two-fold increase in the number of direct-route clearances actually issued to aircraft when controllers were using the CPTP system. The ability of CPTP to confirm that a trial trajectory resolves the conflict without creating any other conflicts was consistently identified by the controllers as one of its most powerful features.