Kotegawa Figure 7. CPDS horizontal and vertical profile display snapshot. The ACAS XU CA flight test was an enormous success of historical significance. It demonstrated and validated the horizontal and vertical alerting functions, coordination techniques, autoresponse, and the use of multiple surveillance sources for CA. This flight test also marked the first time that an unmanned aircraft CA system was flown without artificial offsets; the lessons learned and safety build up approach will provide a path forward for future flight tests. In addition to this accomplishment several other historical firsts include: C Demonstrated horizontal CA C ADS-B as the sole surveillance source for CA C Responsive coordination interoperability with TCAS C Active coordination emulation in live flight C Automaneuvering on an unmanned aircraft for CA C SELF-SEPARATION FLIGHT TEST RESULTS Self-separation is a preventive measure carried out by the UAS pilot to mitigate a UAS from entering a collision avoidance scenario. The pilot is provided with nearby air traffic situational awareness through a dedicated display that also recommends maneuvers to maximize the distance and safety from other airborne objects detected by the sensors. Three SS systems - CPDS, Autoresolver, and StratWay+ were assessed in this flight test and are described in this section. Details on StratWay+ are omitted from this article as analysis was still underway at time of publication. CPDS Two unmanned aircraft tested for CA without artificial offsets The data collected and the benchmarks achieved during this flight test will serve the unmanned aircraft community by informing surveillance requirements and engagement with the operational community on standards and measures of performance. The interactions with the community that result from this will help inform future iterations of ACAS XU logic, as the system is developed and integrated with SS functionality. Full results and analysis will be SEPTEMBER 2016 available in the FAA ACAS XU Initial Flight Test Report scheduled to be released August 2015 [7]. CPDS is an SAA display developed by GA-ASI to enable a Pilotin-the-Loop SS concept [8]. Figure 7 displays a snapshot of the CPDS running under a simulated encounter. CPDS is composed of horizontal (top) and vertical (bottom) cross-sections of the conflict geometry, providing the pilot an intuitive, three-dimensional understanding of nearby traffic/associated threats via "no-go" heading bands and conflict probes (areas to avoid due to projected loss of well clear). Many of its design requirements follow from DO317B [9] but its modular architecture allows flexible implementa- IEEE A&E SYSTEMS MAGAZINE 59