Sense and Avoid Operator Separation of Unmanned Aircraft in Conflict Trajectories

This study explored the ability of operators to provide separation between three unmanned aircraft using basic cockpit traffic displays. Four groups of three general aviation, instrument-rated pilots flew cross-country flights controlling simulated twin-engine unmanned aircraft systems (UAS). They were required to maintain 2 nautical miles (nmi) horizontal and 500 ft vertical separation from all other aircraft. To examine the effect of two important safety factors, the flights were conducted with and without communication among the operators and with and without variable accuracy in the displayed traffic location due to degraded sensor quality. Twenty four different three-dimensional traffic conflict trajectories with three UASs, were repeated randomly for each of the four experimental conditions for each group.Of the 1152 aircraft encounters 12.8% were in violation of separation minimums. Eighteen of these were closer than 400 ft vertically or 1.6 nmi horizontally. The minimum separation of all aircraft ...