Definition
In risk assessment, severity is the measure of how serious the consequences of an event would be if it occurred, ranging from negligible to catastrophic. It is one of two factors used to evaluate risk, the other being likelihood (how probable the event is).
Plain English
How bad it would be if something went wrong. A minor inconvenience is low severity; an accident causing injury or loss of the aircraft is high severity.
Context Anchor
Used when assessing flight risk before or during a flight, especially when deciding whether a risk is acceptable or needs to be reduced.
Derivation
From the Latin severus, meaning 'strict' or 'serious.' In risk management, it refers to how serious the outcome would be — not how strict the rules are.
Why Pilots Care
It helps pilots prioritize which risks require immediate action or mitigation to ensure safety.
Grounding Statement
If the possible result is injury, major aircraft damage, or loss of control, the severity is high even if the chance of it happening is small.
Intuition Check
Do not confuse severity with likelihood. Severity means how bad the result would be; likelihood means how probable it is.
Example Sentence 1
When evaluating the flight, the instructor rated the severity of an inadvertent flight into icing conditions as high due to the lack of de-icing equipment.
Example Sentence 2
In the risk matrix, a minor incident like a tire blowout has lower severity compared to a runway incursion.