Plain English Meaning
Mistakes caused by leaving something out, like forgetting to do a step, skipping a check, or missing a piece of information that should have been noticed.
Full Definition
Mistakes that occur when a pilot fails to perform a required action, such as missing a checklist item, skipping a radio call, or neglecting to monitor an instrument. In situational awareness terms, errors of omission happen when relevant information is overlooked or left out of the pilot's mental picture, leading to incomplete or inaccurate awareness of the flight situation.