Effects of UAS Performance Characteristics, Altitude, and Mitigation Concepts on Aircraft Encounters and Delays

Introduction of Unmanned Aircraft Systems (UAS) into positively controlled airspace may cause greater per-aircraft impact on the National Airspace System than existing traffic because UAS aerodynamic performance and mission types are often different from aircraft that typically fly in positively controller airspace (i.e. commercial passenger traffic). This paper examines the impact new UAS operations will have on existing aircraft and measures that impact by the number of predicted conflicts and associated conflict resolution delays that occurred in fast-time simulation. The two conflict metrics are quantified as a function of the UAS altitude and cruise speed. Two mitigation approaches are also investigated: increasing horizontal separation requirements for UAS and “burdening” UAS with the responsibility to execute all resolution maneuvers when possible. Results indicate that en route conflict maneuver delay for existing traffic because of new UAS operations can be nearly eliminated by burdening UAS with the responsibility to execute conflict resolution maneuvers and maintaining the current en route horizontal separation requirement of five nautical miles from other aircraft.