Operational integration of UAS into the ATM system

Unmanned Aircraft Systems (UAS) are a novel component in the aviation system, offering advancements which may open new and improved civil and military applications. In general employing UAS is considered useful in missions which are either too undemanding (i.e. steady border monitoring) or too dangerous (i.e. natural disaster reconnaissance, adverse terrain or weather) to employ manned aircraft. Unmanned aircraft systems are therefore becoming increasingly important even for non-military and civil applications. A main challenge however is the integration of UAS into the existing and future Air Traffic Management (ATM) system. Integration of UAS into non-segregated airspace remains a major goal to be solved for future acceptance of these systems. Currently, most civil and military UAS operations are taking place in segregated airspace so that collision avoidance and separation with other traffic is of no concern. To further enable the UAS operational scope, Unmanned Aircraft (UA) must be able to fly in airspace where other traffic is operating as well. In this paper, simulation trials are presented in which UAS are operating together with manned aircraft in non-segregated airspace. Different simulation scenarios were hereby investigated. The applied scenarios are based on the execution of two different mission types, a transfer and a surveillance flight. In the simulations the potential risk of collisions in different flight phases of the UA and the applicability of prevailing Air Traffic Control procedures for manned aircraft were examined. Flying UAS in non-segregated airspace may generate risks to other airspace users if they fail to follow the rules valid for this particular airspace. To investigate the potential risks, two exemplary failure scenarios of UAS were integrated into the simulation scenarios. In addition, air traffic controllers (ATCO) were surveyed with regard to workload and their evaluation of the maintenance of safety within the different scenarios