“Introducing a New Concept to Explain Pilot Adaptation to Abnormal and Emergency Situations”

In managing abnormal and emergency situations during flight, pilot situational awareness and adaptation to events are key factors in successful crisis mitigation. However, it is widely recognized that workload, stress, and surprises during unexpected events often degrade human performance, potentially leading to impaired cognitive states. Among these, mechanisms underlying the startle effect, delayed responses, and cognitive "freezing" remain only partially understood. We propose the introduction of the concept of a "dissociative state" as an adaptive response to cope with these situations and advocate its inclusion in a revised taxonomy for incident and accident analysis. This novel approach takes a multifactorial perspective, with the dual objectives of understanding the role of dissociative states as adaptive mechanisms and proposing design adaptations, operational procedure revisions, and training strategies to better support pilots in managing performance during high-stress events. To explore this, a detailed analysis (crew actions and verbalisations) of 50 official accident reports involving large commercial aircraft, encompassing various manufacturers was conducted, beginning by a chronological detailed event description. We evaluated crew actions and verbalizations, using two taxonomies: one based on traditional concepts such as surprise, stress, and workload, and the other incorporating dissociative states as potential contributors to observed behaviors. Dissociative states, documented in existing literature as disorganized information encoding associated with situation novelty, stress and workload, should not necessarily be considered as a performance degradation factor for flight operations, as they are often transient. Our hypothesis is that dissociation serves as a temporary adaptive response when pilots encounter surprise, stress, workload, and intense emotional states. We identified several indicators—such as absorption, confusion, amnesia, and loss of control over behavior, etc.) —that support the existence of dissociative states, providing strong arguments for incorporating this concept into existing Human Factors (HF) taxonomies. Our findings suggest that dissociative states are more frequently observed in cases involving severe outcomes. This phenomenon could enhance cockpit design, pilot training, and operational procedures in future aircraft development.