PASSIVE FINAL APPROACH SPACING TOOL T. J. Davis, D. R. Isaacson, J. E. Robinson III, W. den Braven, K. K. Lee, and B. Sanford Abstract A prototype decision support tool for terminal area air traffic controllers, referred to as the Final Approach Spacing Tool (FAST), was recently evaluated in operation with live air traffic at the Dallas/Fort Worth, Texas Airport. Controllers utilized FAST's runway and sequence advisories to manage and control arrival traffic during more than twenty-five peak rush traffic periods. This paper presents the results of these tests, describing data on FAST's impact on airport capacity, in-trail separation on final approach, safety, and controller workload. Results demonstrate airport throughput increases of more than 13 percent with no negative impact on controller workload or safety.