Plane & Pilot
Tuesday, February 11, 2014

Understanding VFR Into IMC Accidents

A study of situational and pilot-related factors

However, there was also a positive correlation between flight time and VFR into IMC accidents, meaning that pilots involved in these accidents had higher flight time. Coupled with the previous finding, it appears that higher-time, lower- certification-level pilots are more at risk.

Of course, higher-time pilots are more likely to be exposed to poor weather. But it also speaks to some of those hazardous attitudes we should all avoid, specifically overconfidence in one's ability to cope with weather, that may exceed expectations and abilities. Some other relationships uncovered by the current study were that older pilots were less likely to be involved in these types of accidents.
Weather-briefer training could be modified or augmented to better provide pilots with more emphasis on warnings and hazards that may positively influence pilot decision-making.
Also, pilots flying in mountainous terrain were less likely to be on a flight plan, perhaps counterintuitive to what might be considered good practice. Other factors, such as time of day and air traffic control (ATC) communications, had weak associations with VFR into IMC, indicating such events were less likely to occur during the day and when in communication with ATC. These findings are intuitive, as poor weather is easier to see and avoid during the day, and ATC can provide assistance to pilots in trouble especially in high terrain.

Lessons Learned
So what are the "takeaways" from this study? One is that perhaps we need to examine pilot weather education. Clearly, those with lower certification levels could benefit from situational-based training (SBT) that concentrates on weather decision-making and risk assessment. With the high incidence of VFR into IMC in elevated terrain, more focus should be paid to SBT in mountainous terrain, complete with their unique weather attributes. This could easily be reproduced in simulation.

Moreover, weather-briefer training could be modified or augmented to better provide pilots with more emphasis on warnings and hazards that may positively influence pilot decision-making. Other findings, such as the fact that pilots with low certification levels and high flight times having a higher incidence of VFR into IMC, beckons improved recurrent and flight review training to include SBT and hazardous attitude evaluation specifically related to flights in or around rapidly changing or deteriorating weather conditions.

Also, the findings indicate some actions to mitigate risk in marginal weather conditions, such as avoiding night flights in such conditions, filing of flight plans and using all available resources to help keep them safe, namely interaction with ATC. Thankfully, studies such as these highlight improvements that pilots, as well as the industry as a whole, can make to improve the knowledge base and amend operational habits to make flying safer.

David Ison, Ph.D., holds a masters of aeronautical science from Embry-Riddle Aeronautical University-Worldwide. He's an assistant professor of aeronautics and program chair of the masters of aeronautical science program. A copy of his research for this study can be requested by contacting Ison at This e-mail address is being protected from spambots. You need JavaScript enabled to view it .


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