The Hazards of Confirmation Bias in Aviation

By Shanon Kern

A wise pilot once told me, “If you’re planning to fly somewhere, be ready to drive.” At the time, I didn’t fully understand the relevance of this statement. In my inexperienced student pilot mind, I believed that I would be able to plan a vacation, reserve the plane months in advance, and fly to my intended destination. I was unaware that in order for a scenario like this to work out, a lot of external factors would have to fall perfectly in place. 

According to the NTSB database, in 2013 there were a total of 49 part 91, aviation related accidents where instrument meteorological conditions (IMC) prevailed. As I searched through the database and read the weather reports, I was left wondering why a pilot would choose to fly in such adverse weather conditions? After reading several factual NTSB reports, a pattern started to develop. The majority of the flights were not VFR flights into IMC conditions. They were cross-country flights where the weather was questionable, at best, from the start.  

After reading through the reports, I was reminded of an often-cited human condition of the mind known as confirmation bias. Confirmation bias is the tendency to choose, search for, and interpret information in a way that confirms our beliefs or hypothesis. In aviation, confirmation bias can be devastating. It can lead to an inaccurate assessment of weather risks, a tendency to cherry pick information that benefits a desire to fly or to stay on a schedule. For most pilots, myself included, there is an excitement in planning a cross-country flight. As we begin to check weather and prepare for a flight, our minds are naturally well adapted at finding information that leads to our desired outcome. There is a natural inclination to look for positive information that will allow us to complete the flight and ignore or downplay information that could lead to disappointment.

A hot topic among flight schools, safety officials, and government regulators is aeronautical decision making (ADM). Pilots are taught to recognize and remedy the five hazardous attitudes: Resignation, Anti-authority, Impulsivity, Invulnerability, and Macho. Confirmation bias can manifest in any one of these hazardous attitudes. Recognizing that we all possess a tendency toward confirmation biases of one form or another is the first line of defense in understanding the danger it could pose. 

Effective aeronautical decision-making begins at the earliest stages of planning a flight and should end well after the wheels touch the ground.