A HUMAN FACTORS EVALUATION OF ACTIVE FINAL APPROACH SPACING TOOL CONCEPTS Cheryl Quinn and John E. Robinson, III Abstract This paper summarizes the human factors aspects of the development of an air traffic control decision support tool known as the Active Final Approach Spacing Tool (aFAST). Active FAST will provide heading and speed advisories that will allow Terminal Radar Approach Control (TRACON) air traffic controllers to space aircraft more precisely on final approach. The human factors challenges include the design of the advisory format, timing of the presentation of advisories as well as the definition of the user interaction necessary for a daily-use operational system. Another key issue is the impact of the use of color displays on aFAST implementation. Initial shadow simulations were conducted to determine a nominal advisory presentation format. Findings from these studies are discussed and plans for further laboratory and field evaluations of aFAST are outlined.