Definition
A condition in which the airplane is about to run out of usable fuel, leaving the pilot with very little time before the engine stops producing power. It is treated as an emergency requiring immediate action, including a landing as soon as possible and, when appropriate, a declaration of emergency to ATC.
Plain English
The airplane is about to run out of fuel. Not low. Not concerning. About to stop running. The pilot needs to land now, not soon.
Context Anchor
Encountered during emergency approach and landing decisions, especially when a pilot must choose the nearest safe place to land before the engine quits.
Derivation
Imminent comes from the Latin imminere, meaning 'to overhang' or 'to threaten' — something hanging over you that is about to happen. Exhaustion comes from the Latin exhaurire, 'to draw out completely.' Together: the fuel is about to be completely drawn out, and that moment is right on top of you.
Why Pilots Care
It indicates that engine power loss is seconds to minutes away, requiring immediate commitment to an emergency landing to avoid an in-flight total power loss.
Grounding Statement
Picture being airborne with the fuel nearly gone and no time left to continue a normal flight plan.
Intuition Check
Do not read this as just “low fuel.” Imminent fuel exhaustion means running out of fuel is expected very soon, and the situation already requires emergency action.
Example Sentence 1
Faced with imminent fuel exhaustion, the pilot declared an emergency and accepted vectors to the nearest airport.
Example Sentence 2
The training scenario introduced imminent fuel exhaustion to let the student practice a landing with the engine still running but power loss only moments away.