Definition
A combustible substance that, when mixed with air and ignited inside an engine, releases energy used to produce thrust or mechanical power. In aviation, fuel typically refers to aviation gasoline (avgas) for piston engines or jet fuel (kerosene-based) for turbine engines.
Plain English
The liquid an aircraft burns to make its engine run. Different aircraft use different types: piston engines burn avgas, and jet engines burn jet fuel.
Context Anchor
Seen during fueling, preflight inspection, fuel sampling, maintenance, and any discussion of chemical exposure around aircraft.
Derivation
From Old French 'fouaille,' meaning material for a fire, ultimately from Latin 'focus,' meaning hearth. The aviation meaning carries the same idea — the substance that feeds the fire inside the engine.
Why Pilots Care
Improper handling can cause immediate health effects such as dizziness or skin damage, compromising pilot fitness and operational safety.
Grounding Statement
If fuel spills on your hand or clothing, it is not just a mess; it is a chemical exposure and a fire risk until it is cleaned up properly.
Intuition Check
Do not think of fuel only as the gasoline you put in a car. In aviation, fuel may be aviation gasoline or jet fuel, and the fumes can matter as much as the liquid.
Example Sentence 1
Before each flight, the pilot drains a small sample of fuel from each tank to check for water or contamination.
Example Sentence 2
A small fuel spill on the ramp requires immediate containment to prevent skin contact or environmental contamination.