Definition
A carburetor that meters fuel into the engine's induction airflow using a float-controlled valve to maintain a constant fuel level in a small chamber, from which fuel is drawn into the airstream by the pressure drop created at a venturi. Air entering the carburetor accelerates through the venturi, lowering its pressure relative to the fuel chamber, which pushes fuel out through a discharge nozzle and atomizes it into the air on its way to the cylinders.
Plain English
A device that mixes fuel with air for the engine. A small float inside it keeps the fuel level steady, like the float in a toilet tank, and the moving air sucks fuel out and sprays it into the airflow heading to the cylinders.
Context Anchor
Seen in piston-engine induction system discussions, especially when learning how fuel and air are mixed before entering the engine.
Derivation
‘Carburetor’ comes from the French ‘carbure’ (a carbon compound) plus the suffix ‘-etor,’ meaning a device that combines fuel (a carbon compound) with air. ‘Float-type’ simply describes how this kind of carburetor regulates its fuel level: with a float.
Why Pilots Care
It supplies stable fuel delivery across changes in aircraft attitude and prevents engine stoppage from fuel starvation or flooding.
Analogy
It works somewhat like the float in a toilet tank: as the liquid level changes, the float moves and helps control how much more liquid is allowed in. In the carburetor, that controlled fuel level helps the engine get a steady mixture.
Intuition Check
“Float” does not mean the carburetor floats in the aircraft. It means the carburetor has a buoyant part inside that floats on fuel and helps control the fuel level.
Example Sentence 1
Because the trainer has a float-type carburetor, the instructor emphasized applying carburetor heat before reducing power for the descent.
Example Sentence 2
In the preflight checklist the student verified that the float-type carburetor was functioning before engine start.