The condition of Spatial Disorientation (SD) is thought to be a main contributor to aviation mishaps and accidents in the aviation industry. This study examined the cognitive effects of SD among general aviation (GA) pilots in a realistic flight environment using an operationally relevant secondary task. GA pilots (n = 34) flew four scenarios in a Pilatus PC-7 flight model, simulated using a hexapod motion platform and virtual reality visuals. During each scenario, participants experienced both regular and disorienting flying conditions. The four SD events were "false horizon", "featureless terrain", "the leans", and a novel "scattered clouds" event. Cognitive performance was measured through a secondary checklist task's completion times and error rates. The findings show that completion times, error rates, as well as heading deviations increased significantly under SD compared with baseline conditions, particularly for "the leans" and "scattered clouds". Subjective ratings indicated that participants were aware of SD cues, that they perceived increased aviating focus and SD intensity, and that scenarios provided high SD awareness training value, particularly when the secondary task was included. Overall, SD impairment on cognitive and control performance is highlighted through an operationally relevant secondary task, with implications for designing simulator-based training to raise awareness of SD effects.