Definition
A diversion is a change from the originally planned route or destination, in which the flight proceeds to an alternate airport or alternate routing rather than the one originally filed or assigned. Diversions occur for reasons such as weather below minimums, airport closure, mechanical issues, fuel considerations, traffic flow management, or medical emergencies.
Plain English
When a flight cannot or should not continue to its planned destination, the pilot changes course and lands somewhere else instead. That change is called a diversion.
Context Anchor
Seen in aviation messages, air traffic control information, flight plan changes, and reports when an aircraft changes its route or destination.
Derivation
From the Latin divertere, meaning 'to turn aside' (di- 'aside' + vertere 'to turn'). In aviation, it keeps that exact sense: turning aside from the planned path to go somewhere else.
Why Pilots Care
A diversion changes fuel requirements, landing distance calculations, and passenger or cargo handling, all of which must be reassessed before continuing.
Intuition Check
Diversion does not mean entertainment or a distraction here. In aviation, it means a deliberate change away from the planned route or destination.
Example Sentence 1
With the destination reporting a thunderstorm overhead, the crew elected an early diversion to the filed alternate.
Example Sentence 2
ATC cleared the flight for a diversion when the primary runway was closed by an incident.