

Validation of unmanned aircraft systems to enable integration in civil airspace

Unmanned aircraft systems (UAS) are increasingly seen both in military and civil use. The aircraft flies without a pilot on board and is controlled from the ground.

The possible integration of these systems in the airspace outside restricted areas presents a great challenge and was investigated using simulations and flight tests of remote-controlled UAS with the involvement of DFS. "See and avoid" is the principle on which collision avoidance in air traffic is based. As there is no direct sight by the pilot of an UAS, technical solutions for detection and avoidance need to be found.

A possible concept for the safe integration is based on transponder equipment in the UAS and the surrounding traffic. The UAS operator on the ground is supported by a traffic alert and collision avoidance system in detecting and resolving conflicts. The input data for the system are composed of radar data for the UAS and the surrounding traffic. This concept was investigated in real flight tests, where the UAS flew within an active restricted area. In the first step, the UAS was flown through simulated traffic. In the second step, the simulated surrounding traffic was replaced with a real aircraft and proximity situations were flown.

The real flight tests showed that an integration of UAS using radar display of traffic and the use of a detect-and-avoid system seems to be possible in principle. A final decision must await further work.