Definition
A kerosene-based fuel refined for use in turbine engines (turbojet, turbofan, turboprop, and turboshaft). It has a higher flash point, lower volatility, and lower freezing point than aviation gasoline, and burns through continuous combustion rather than spark ignition. Common grades include Jet A and Jet A-1 (civil) and JP-4, JP-5, and JP-8 (military).
Plain English
The fuel that turbine engines run on. It is closer to kerosene than to the gasoline used in piston aircraft, and it is not interchangeable with avgas.
Context Anchor
Seen during aircraft fueling, fuel-system maintenance, fuel contamination checks, and powerplant discussions for turbine-powered aircraft.
Derivation
Named simply for its use in jet (turbine) engines, as opposed to the aviation gasoline used in piston engines. The word 'jet' here refers to the engine type, not the speed of the aircraft.
Why Pilots Care
The correct grade and cleanliness of jet fuel directly affect engine reliability and prevent in-flight power loss from contamination or incorrect fuel type.
Intuition Check
Do not assume “jet fuel” means any fuel used by a fast airplane. In aviation, it means a specific kerosene-type fuel for turbine engines, not aviation gasoline.
Example Sentence 1
Before fueling the turboprop, the technician confirmed the truck was carrying Jet A and not avgas.
Example Sentence 2
Mechanics drained a fuel sample to check for water in the jet fuel during the preflight inspection.