BACKGROUND: Fighter pilots' Team Situation Awareness (TSA) has been studied from the perspective of TSA accuracy, which represents how closely the pilots' collective knowledge is aligned with the real world. When TSA accuracy is low, the pilots can have similarly or dissimilarly inaccurate SA. The concept of TSA similarity represents the similarity of team members' collective knowledge. This paper investigates how TSA accuracy and similarity of F/A-18 pilots are associated with performance.METHOD: Data were extracted from simulated air combat missions. Performance and TSA were investigated in 58 engagements. The accuracy and similarity of pilots' SA were elicited and performance was evaluated. TSA accuracy and similarity were analyzed with respect to the flights' performance, and the independent variables were events in which the flights initiated engagements with enemy aircraft versus events in which the flights were engaged by enemy aircraft.RESULTS: With the mentioned events as the main effect, there were statistically significant differences at all levels of TSA accuracy and similarity. With performance as the main effect, there were also significant differences at all levels of TSA accuracy and similarity. TSA accuracy and similarity were superior in offensive engagements and when engagements were successful.DISCUSSION: The main contribution of this paper is the extension of the concept of TSA similarity to air combat: both TSA similarity and accuracy were higher when the flight was engaging the enemy aircraft, compared to situations when the flight itself was being engaged. The results also suggest that low TSA accuracy and similarity have a statistically significantly negative impact on the flights' performance.Mansikka H, Harris D, Virtanen K. Accuracy and similarity of team situation awareness in simulated air combat. Aerosp Med Hum Perform. 2023; 94(6):429-436.