A drone is shown flying during a test of Unmanned Aircraft Systems Traffic Management (UTM) technical capability Level 2 (TCL2) at Reno-Stead Airport, Nevada in 2016. During the test, five drones simultaneously crossed paths, separated by different altitudes. Two drones flew beyond visual line of sight and three flew within line-of-sight of their operators. More UTM research followed, and it continues today.
Image credit: NASA Ames/Dominic Hart