UAS Contingency Management: The Effect of Different Procedures on ATC in Civil Airspace Operations

UAS currently lack key capabilities required to routinely integrate with the current Air Traffic Management (ATM) system, including standardized and predictable procedures for managing off nominal or contingency events, especially those that are specifically related to UAS and their unique communications architecture [i.e., loss of the command and control communications link(s). A simulation experiment was conducted to examine the effects of a variety of currently-employed UAS contingency procedures on sector safety and efficiency, and Air Traffic Controller (ATC) workload. ATC participants were tasked with maintaining safe separation standards in a busy Terminal Radar Approach Control (TRACON) sector that included a single UAS. During different trials, the UAS would execute one of five contingency types, including one trial with no contingency (i.e., baseline), three different contingency procedures for the loss of command and control link, and one emergency landing procedure. Objective aircraft separation and sector throughput data, workload ratings, situation awareness ratings, and subjective ratings regarding the safety and efficiency of UAS operations in the NAS were collected. Results indicated that the simulated UAS contingency procedures had no significant impact on objective measures of safety and efficiency compared to the baseline. Further, there were no significant differences in subjective workload and situation awareness ratings between the baseline and any of the contingency procedures.