The training effectiveness literature has paid little attention to the potentially dynamic interaction of individual differences with various phases of training in determining ultimate training success. This study investigates the role of individual differences in explaining the transfer of learning from 1 phase of training to another among pilot trainees in a multistage, aviation training program. Using 3 of the Big Five factors (Conscientiousness, Emotional Stability, Openness to Experience), the results showed these measures to contribute to the prediction of the number of hours it took for trainees to attain their private pilot's license. Significant interactions between some of these measures and success on an earlier, simulator phase of the training program were also found. The results are discussed in terms of both the role of individual differences in training research as well as the broader issue of transfer of learning between phases of training.