Definition
An electrically driven pump that supplies fuel from the tank to the engine under pressure, used to supplement or back up the engine-driven fuel pump. It ensures positive fuel flow during engine start, takeoff, landing, high-altitude operations, and any condition where the engine-driven pump may not provide adequate pressure.
Plain English
An electric pump that pushes fuel from the tank toward the engine. It's used during critical phases of flight and as a backup if the engine's own fuel pump fails.
Context Anchor
Seen in engine failure checklists, starting procedures, and airplane operating handbook procedures for fuel pressure or fuel flow problems.
Derivation
"Boost" means to push up or assist. The pump boosts (assists) fuel delivery beyond what the engine-driven pump provides on its own.
Why Pilots Care
It prevents fuel starvation or vapor lock that could cause engine stoppage during critical phases of flight.
Intuition Check
Do not think of the fuel boost pump as something that adds extra power to the engine. It boosts fuel pressure and fuel flow; it does not boost engine horsepower by itself.
Example Sentence 1
Before takeoff, the pilot turned on the fuel boost pump and verified fuel pressure was in the green arc.
Example Sentence 2
Leaving the fuel boost pump on during the initial climb helped avoid vapor lock in warm weather.