Definition
A device that warms fuel before it reaches the engine or fuel control unit, raising its temperature enough to prevent ice crystals from forming in the fuel and blocking filters or fuel lines. Typically uses heat drawn from engine oil, bleed air, or exhaust as the heat source.
Plain English
A small heater in the fuel system that warms the fuel on its way to the engine, so any tiny ice particles in the fuel melt before they can clog things up.
Context Anchor
Seen in fuel-system descriptions, cold-weather operation, and engine operating procedures, especially on aircraft that fly high or in very cold air.
Why Pilots Care
Prevents fuel icing that can cause power loss or engine flameout in low temperatures.
Intuition Check
A fuel heater does not heat the cabin and is not used to make the engine warm up faster. It heats the fuel in the fuel system so the engine continues receiving a steady fuel supply.
Example Sentence 1
During the climb to cruise altitude, the pilot monitored the fuel temperature gauge and activated the fuel heater when the reading approached the icing range.
Example Sentence 2
During the preflight inspection the crew confirmed the fuel heater was operational for the expected cold-weather flight.