Definition
A component in an aircraft engine's induction system that controls the amount of fuel mixed with incoming air before it enters the cylinders. The two main types are the carburetor and the fuel injection system, both of which deliver the correct fuel-to-air ratio for the engine's operating conditions.
Plain English
The part of the engine that decides how much fuel to add to the air going into the cylinders. It makes sure the mixture is right for the power setting and altitude.
Context Anchor
Seen in induction system discussions, especially when comparing carburetors and fuel-injection systems.
Derivation
‘Meter’ comes from the Greek ‘metron,’ meaning ‘measure.’ A fuel metering device literally measures out the fuel, controlling how much is delivered rather than just letting it flow freely.
Why Pilots Care
Proper metering prevents engine roughness, power loss, or damage from overly rich or lean mixtures during flight.
Analogy
It is like a controlled faucet for fuel: as the engine needs more or less, the device changes the flow instead of simply being open or closed.
Intuition Check
Do not read “fuel metering device” as a fuel gauge. It does not just show how much fuel exists; it controls how much fuel goes to the engine.
Example Sentence 1
On this aircraft, the fuel metering device is a float-type carburetor mounted below the engine.
Example Sentence 2
During climb, the fuel metering device automatically reduces fuel delivery to maintain the correct mixture as air density decreases.