Assessing Safety for U-space Airspace: A Simulation Study of UAS Impact on Low-Altitude Helicopter Operations in Zurich

This paper proposes a quantitative methodology to use fast-time simulation to support the assessment of collision risk between Uncrewed Aircraft Systems (UAS) and crewed aircraft in the context of U-space airspace risk assessment. Airspace risk assessment is specifically required of European Union member states by the U-space regulation in order to designate U-space airspace for UAS operations. To illustrate the proposed methodology, a use case provided by the Swiss Federal Office of Civil Aviation (FOCA), was simulated. In this use case, UAS operations within a volume of airspace selected to represent U-space airspace interact with Helicopter Emergency Medical Services (HEMS) on historical HEMS routes in the city of Zurich, without mitigations to prevent collision. Using Monte Carlo methods in fast-time simulation and a four step quantitative methodology, we demonstrate that the probability of mid-air collision (MAC) between uncrewed and crewed aircraft can be estimated efficiently without historical UAS track data.