Plain English Meaning
You did exactly what you meant to do, but what you meant to do was wrong. The error was in the thinking, not in the doing.
Full Definition
An error caused by faulty thinking, planning, or decision-making — where the action carried out was the one intended, but the underlying judgment, knowledge, or choice was wrong. Distinguished from a slip, which is an unintended action made while attempting to do the right thing.
Context Anchor
Used in aviation training and debriefs when separating a wrong decision from a simple execution error.
Derivation
From Old Norse 'mistaka,' meaning 'to take in error' or 'take wrongly.' The sense of taking the wrong path or wrong choice carries through to the aviation use: the pilot deliberately picked an option, but picked the wrong one.
Why Pilots Care
Recognizing mistakes helps instructors address causes in judgment rather than just execution .