Definition
A chemical compound, typically diethylene glycol monomethyl ether (DiEGME) or ethylene glycol monomethyl ether (EGME), that is blended into turbine engine fuel to prevent water suspended in the fuel from freezing and forming ice crystals that could block fuel filters or fuel system components at low temperatures.
Plain English
A chemical mixed into jet fuel to stop tiny droplets of water in the fuel from turning into ice when the fuel gets very cold at altitude.
Context Anchor
Seen in aircraft fueling, maintenance, and fuel-system discussions, especially for aircraft operated in cold temperatures or at high altitude.
Derivation
‘Anti-’ comes from Greek meaning ‘against,’ and ‘icing’ refers to ice formation. So the term simply means ‘something added to work against ice forming’ — in this case, ice forming inside the fuel itself, not on the airframe.
Why Pilots Care
Prevents fuel starvation or engine failure caused by ice blocking the fuel supply in flight.
Grounding Statement
If a tiny amount of water is in the fuel and the aircraft climbs into very cold air, the additive helps keep that water from becoming ice that can block the fuel path.
Intuition Check
Anti-icing additive does not mean a fluid sprayed on the wings to remove ice. Here it means a chemical mixed into fuel to help prevent ice inside the fuel system.
Example Sentence 1
Before departure in cold weather, the line crew confirmed that the correct amount of anti-icing additive had been blended into the fuel during refueling.
Example Sentence 2
Even in below-freezing temperatures the anti-icing additive kept the fuel flowing freely through the filters.