Definition
An aircraft cabin heating system that produces heat by burning a small, controlled amount of aviation fuel inside a sealed combustion chamber. Outside air is drawn across the outside of that chamber, warmed by contact with its hot walls, and then ducted into the cabin. The exhaust gases from the burning fuel are kept entirely separate from the cabin air and are vented overboard. Combustion heaters are commonly installed in light aircraft whose engines do not produce enough waste heat for an exhaust shroud (muff) heater to be practical, such as many turbocharged piston aircraft and light twins.
Plain English
A small fuel-burning heater inside the aircraft that warms cabin air by passing it over a hot metal chamber. The flame and its exhaust stay sealed away from the cabin; only clean, heated air is sent inside.
Context Anchor
Seen in aircraft heating-system discussions, cockpit heater controls, preflight checks, and operating instructions for aircraft equipped with an independent cabin heater.
Derivation
Combustion comes from the Latin combustio, meaning 'a burning up.' The name simply tells you how the heat is produced: by burning fuel, as opposed to drawing waste heat from the engine exhaust.
Why Pilots Care
Provides essential cabin warmth in cold conditions, improves comfort and visibility by reducing fogging, and requires monitoring to prevent carbon monoxide buildup.
Grounding Statement
Picture a small, sealed fuel-burning heater in the aircraft that warms cabin air without letting the burned gases mix with the air you breathe.
Intuition Check
Do not assume a combustion heater simply uses leftover engine heat. In this context, it has its own controlled burning process, separate from the engine exhaust system.
Example Sentence 1
Before the first cold-weather flight, the mechanic pressure-tested the combustion heater system to check for exhaust leaks.
Example Sentence 2
During preflight, the instructor explained how to check the combustion heater systems for proper exhaust venting.