Definition
A cognitive tendency in which a pilot unconsciously favors information that supports a conclusion they have already reached, while discounting or ignoring information that contradicts it. In aviation decision-making, it leads pilots to interpret ambiguous cues as evidence that their original plan or assumption was correct.
Plain English
The habit of seeing what you expect to see and brushing aside anything that suggests you might be wrong. Once a pilot decides something is true, the brain starts collecting evidence in favor of that decision and quietly filtering out the rest.
Context Anchor
Seen in aeronautical decision-making, risk management, weather decisions, troubleshooting, and accident discussions.
Derivation
From Latin confirmare, meaning 'to make firm' or 'strengthen.' The term describes how the mind keeps strengthening a belief it has already settled on, rather than testing it.
Why Pilots Care
It can lead pilots to dismiss warning signs or alternative interpretations during preflight planning or in-flight emergencies, increasing the risk of poor decisions.
Analogy
It is like checking only the parts of a weather forecast that support your picnic plans and skipping the part that says thunderstorms are likely. The information was there, but you paid attention only to the part you wanted.
Intuition Check
Confirmation bias does not mean the pilot is careless or dishonest. It means the pilot’s mind may naturally lean toward evidence that supports the plan already in motion.
Example Sentence 1
The instructor warned the student about confirmation bias, explaining that once a pilot commits to landing at the planned airport, every patch of clear sky starts to look like proof the weather is improving.
Example Sentence 2
During the post-flight debrief, the instructor pointed out the student's confirmation bias in assuming the engine roughness was due to carburetor ice without considering other possibilities.