With a focus on psychometric assessment, the current study investigated the extent to which spatial orientation ability (SOA), as conceptualized in the spatial cognition and navigation literature, predicted air traffic conflict detection performance in a simulated free route airspace (FRA). Within a FRA, airspace users have the flexibility to plan flights by selecting preferred routes between predefined waypoints. Despite such benefits, FRA implementation can introduce conflicts that are geometrically complex, and of which would require a high level of SOA engagement. Based on a sample of 20 young adults who have the prospect to become air traffic controllers (ATCOs), we found that response time-based performance on a newly developed computerized spatial orientation test (SOT) predicted time to loss of minimum separation (tLMS)-based performance on a conflict detection task to a moderately large extent under scenarios with high air traffic density. We explained these findings in light of similar or overlapping mental processes that were most likely activated optimally under task conditions featuring approximately equal numbers of outcome-relevant stimuli. We also discussed the potential use of the new SOT in relation to the selection of prospective ATCOs who can demonstrate high levels of conflict detection performance in FRA during training simulations.