In spite of considerable efforts to commercialize large remotely piloted vehicles (RPV), an integration of these RPVs into the existing Air Transportation System (ATS) and Airspace Structure is pending. The purpose of this paper was to assess the risks of an exemplary integration of a Heron 1 type RPV into the existing European air space structure within the current regulatory framework and without the availability of sense and avoid technology. Six incident occurrence scenarios were investigated, based on a modified Fault Tree Analysis and Eurocontrol’s risk matrix. It was found that without the implementation of technological or procedural changes, an integration of a Heron 1 RPV presents a low to medium risk to air traffic. Recommended risk mitigation measures include equipping the RPV-operator with a recognized air picture, equipping the RPV with TCAS, installing a conventional telephone land line between the RPV-operator and air traffic control, and commencing the integration of large RPVs into air traffic at night. Further, simulation and flight based research is necessary to demonstrate whether these control measures would reduce the risk to an overall low level.