Debriefing is routinely used in pilot training. Limited empirical studies, however, have investigated what aspects of debriefing contribute to learning outcomes across professions. In this investigation, we focus on the learning of pilots flying large commercial aircraft in a multi-crew flight deck. The researchers observed, recorded and analysed over 32 biannual simulator training and assessment sessions. Each pilot pair engaged in two kinds of experiences across these two-day assessments: (a) a four-hour simulator session with a one-hour debriefing and (b) a three-hour simulator session with an extended period of debriefing. This preliminary report explores the quality and outcomes of these learning experiences, particularly the efficacy of the simulator-to-debriefing ratio. Thematic analysis of post-debriefing semi-structured interviews with three pilot pairs and their shared flight examiner suggests that appropriate debriefing duration and processes should be determined through considering personal readiness of pilots and situational factors during the training.