An Examination of Unmanned Aircraft Systems Pilots’ Interaction with Air Traffic Control while Responding to Detect and Avoid Conflicts

Abstract

New performance standards for a detect and avoid (DAA) system are being developed to support the broader integration of unmanned aircraft systems (UAS) into the National Airspace System (NAS). One subset of these performance standards will address the minimum DAA display requirements to support pilot performance on maintaining well clear of other aircraft. These performance standards must take into account the current air traffic control (ATC) operational environment. In particular, the DAA system, and pilots’ interactions with that system, must account for the requirement for pilots to request a clearance for deviations from their approved instrument flight rules route. A series of human-in-the-loop (HITL) experiments were conducted to help identify the minimum information requirements for DAA displays. As part of these experiments, several pilot-ATC interaction metrics were collected, such as the amount of time it took pilots to request an ATC clearance prior to executing a maneuver to maintain well clear after the appearance of a DAA alert, and the proportion of time that pilots received an ATC clearance prior to maneuvering. The results indicate that while there was no observed effect of different display configurations on pilots’ interactions with ATC, these interactions were affected by the combination of alerting and operational procedures. When pilots received an unambiguous alert to potential well clear violations in conjunction with operational procedures that specified the expected actions to various alert levels, the time that it took for pilots to notify ATC of he need to maneuver dropped substantially, and the rate of obtaining a clearance increased. The implications of these results for developing performance standards for DAA are discussed.