Definition
A system that routes air through a heated shroud around the engine exhaust before it enters the carburetor, raising the temperature of the induction air to melt or prevent ice forming inside the carburetor.
Plain English
A control in the cockpit that sends warm air into the carburetor to melt ice that can form there and choke the engine.
Context Anchor
You encounter carburetor heat during the before-takeoff engine check, and in flight when conditions could allow ice to form in the carburetor.
Derivation
From 'carburetor' (the device that mixes fuel and air for the engine, from French carburer, to combine with carbon) plus 'heat.' The name simply describes what the system does: it heats the air going into the carburetor.
Why Pilots Care
Carburetor ice can reduce engine power or cause complete stoppage; applying heat restores smooth operation and prevents loss of thrust at critical phases such as takeoff or approach.
Grounding Statement
During the before-takeoff check, selecting carburetor heat should cause a small, expected drop in engine speed if warm air is reaching the intake.
Intuition Check
Do not read carburetor heat as cabin heat or general engine warming. It specifically means heated air sent into the carburetor to prevent or remove ice there.
Example Sentence 1
On final approach with the throttle reduced, the pilot pulled carburetor heat on to prevent ice from forming in the induction system.
Example Sentence 2
When the engine began to run rough in humid conditions the pilot pulled the carburetor heat control to full on and power returned to normal within seconds.