Adaptive training, which personalizes training based on a learner’s skills, has been shown to improve knowledge and increase training efficiency, particularly when difficulty is adapted (Flegal et al., 2019; Obergassel et al., 2022; Vykopal et al., 2022). Such benefits could potentially minimize the time and cost of flight training; however, the effects of different difficulty assessment methods are variable, and there is a lack of adaptive training research in flight training contexts. To address this, we evaluated two adaptive difficulty assessments, including a condition adapted based on performance and a condition adapted based on performance and mental effort, compared to a non-adaptive control in a simulation-based flight training experiment. Thirty flight students completed eight trials with varying difficulty in a between-subjects format to determine if the adaptive conditions improved performance and mental effort compared to the control. All conditions resulted in significant performance improvements from pretest to posttest; however, neither of the adaptive conditions significantly differed from the control. This was likely due to high levels of variability in the sample’s flight experience, which was found to influence the pre-post-performance improvements. However, participants’ mental effort in the adaptive conditions remained at moderate levels, whereas a portion of the control group experienced high levels of mental effort. This suggests that the adaptive strategies may have delivered training at a more appropriate level of challenge; however, the limited amount of training may have prevented this from leading to increased learning outcomes. We present here the methods, results, and theoretical and practical implications of the study.