Two versions of a prototype Free Flight cockpit situational display (Basic and Enhanced) were examined in a simulation at the NASA Ames Research Center. Both displays presented a display of traffic out to a range of 120 NM, and an alert when the automation detected a substantial danger of losing separation with another aircraft. The task for the crews was to detect and resolve threats to separation posed by intruder aircraft. An Enhanced version of the display was also examined. It incorporated two additional conflict alerting levels and tools to aid in trajectory prediction and path planning. Ten crews from a major airline participated in the study. Performance analyses and pilot debriefings showed that the Enhanced display was preferred, and that minimal separation between the intruder and the ownship was larger with the Enhanced display. In addition, the additional information on the Enhanced display did not lead crews to engage in more maneuvering. Instead an opposite trend was indicated. Finally, crews using the Enhanced display responded more proactively, tending to resolve alerts earlier.Johnson, Walter W. and Battiste, Vernol and Delzell, Susanne and Holland, Sheila and Belcher, Sean and Jordan, KevinAmes Research CenterFABRICATION; PERFORMANCE TESTS; PROTOTYPES; AIR TRAFFIC; FREE FLIGHT; DISPLAY DEVICES; TRAJECTORY PLANNING; SIMULATION; MANEUVERS; HAZARDS; COCKPITS; AIRLINE OPERATIONS; A-6 AIRCRAFT...