When building systems, usability is not always considered during the design phase, risking human performance detriments. This is concerning for complex and dynamic systems for which poor usability can negatively affect performance. The cost and time constraints of extensive redesigns make alternative approaches for improving human performance a necessity. We analyzed preliminary narrative data to understand usability issues in a system designed to facilitate performance in a complex military-style task. Five usability themes emerged from our analysis: system complexity, system design, attentional limit, extraneous load, and the desire for reference information. A common complaint was that the task procedure could be simplified, freeing additional time in an already temporally demanding task. Furthermore, we found that issues related to attentional limits were associated with poor stress-coping. We provide recommendations based on Nielsen’s usability components for various usability enhancements that can be used to improve human-system interaction.