Definition
In FAA risk assessment, a likelihood category indicating that a hazard or undesired event will probably occur sometime during the operation, but not frequently. It sits between 'Probable' (likely to occur often) and 'Remote' (unlikely but possible) on the standard risk likelihood scale.
Plain English
It means the event will probably happen sometimes — not all the time, but often enough that you should plan for it.
Context Anchor
Seen in risk assessment discussions, especially when judging how likely a hazard is before a flight or during training.
Derivation
From Latin 'occasio,' meaning 'opportunity' or 'occurrence.' In risk language, it points to events that occur from time to time — not constantly, but more than rarely.
Why Pilots Care
Rating a hazard as 'Occasional' rather than 'Remote' or 'Probable' changes the overall risk score, which can drive whether a flight is acceptable, needs mitigation, or should be cancelled. Misjudging likelihood undermines the whole risk assessment.
Intuition Check
Occasional does not mean “almost never” or “not important.” In risk assessment, it means the event can happen sometimes and should be considered.
Example Sentence 1
The instructor rated the likelihood of encountering moderate turbulence on the cross-country as Occasional and briefed the student on how to handle it.
Example Sentence 2
During the preflight briefing the instructor noted occasional icing possible in the clouds above 8000 feet.