Decision-Making Cues and Triggers in Proficient Pilots During Inadvertent Encounters with Instrument Meteorological Conditions

This study investigates the cues and triggers proficient pilots use when inadvertently encountering instrument meteorological conditions under visual flight rules. Given the high fatality rate associated with such scenarios, identifying these cues and triggers and understanding how proficient pilots use them are essential for developing targeted training programs and flight deck support systems. A scoping literature review was conducted, followed by research interviews with seven proficient pilots to verify and expand upon the findings. Identified visual cues included horizontal and surface visibility, cloud ceilings, and terrain clearance, followed by cloud proximity and cloud type. Meteorological cues such as temperature-dew point spread and wind shifts also influenced diversion decisions. Decision triggers included forecast mismatches, rapid weather changes, and local weather trends. These unexpected in-flight weather changes, which conflicted with pilots’ planned conditions, were influential, as proficient pilots conducted thorough preflight weather briefings. Additional decision triggers included personal minimums and terrain awareness, which indicate the importance of risk assessment. They employed multi-cue integration strategies, cross-checking observations with flight deck weather tools to maintain situational awareness. These findings support the development of scenario-based training and decision-support systems grounded in naturalistic decision-making, enhancing pilots’ information acquisition and integration skills.