Definition
A kerosene-based turbine engine fuel used in civil aviation in the United States, with a freezing point of -40°C or below and a flash point around 38°C. It is the standard fuel for jet engines and turbine-powered aircraft in domestic operations.
Plain English
The standard fuel used by jet and turbine aircraft in the U.S. It is a refined kerosene rather than gasoline, designed to stay liquid at the very cold temperatures found at high altitude.
Context Anchor
Pilots encounter Jet-A Fuel during fueling, on fuel cap placards, in aircraft manuals, on fuel orders, and during preflight checks of turbine aircraft.
Derivation
The 'A' designates the U.S. domestic grade in the Jet-A / Jet-A-1 / Jet-B family. Jet-A-1 is the international version with a lower freezing point (-47°C), and Jet-B is a wide-cut blend used in very cold climates. The 'Jet' simply refers to its use in jet (turbine) engines.
Why Pilots Care
Using the wrong fuel type can damage engines or cause in-flight power loss.
Intuition Check
Do not assume Jet-A Fuel is only for pure jet airplanes. Many turboprops and turbine helicopters also use Jet-A Fuel. Do not confuse Jet-A Fuel with aviation gasoline used in many piston-engine aircraft.
Example Sentence 1
Before signing the fuel slip, the captain confirmed the truck had loaded Jet-A and not Jet-A-1.
Example Sentence 2
Because Jet-A Fuel has a low freezing point, it remains fluid at the cold temperatures encountered in high-altitude flight.