Definition
One of the major design classifications used to describe a reciprocating aircraft engine, referring to how heat produced by combustion is removed from the cylinders. The two methods used in aircraft are air cooling, where airflow passes over finned cylinders, and liquid cooling, where a coolant is circulated through jackets around the cylinders and then through a radiator.
Plain English
How the engine gets rid of the heat it makes when it runs. Aircraft engines do this either by letting outside air blow over the cylinders, or by pumping liquid around them to carry the heat away.
Context Anchor
Seen when engines are described or classified in aircraft manuals, ground school, and discussions of engine operation.
Why Pilots Care
Choosing or understanding the correct cooling method prevents overheating that can cause power loss or engine damage.
Grounding Statement
A running engine constantly makes heat; the method of cooling is the path that heat takes away from the engine.
Intuition Check
Do not read this as cabin cooling or air-conditioning. Here it means the way the engine removes its own heat.
Example Sentence 1
Reciprocating engines are classified by cylinder arrangement, by operating cycle, and by method of cooling.
Example Sentence 2
A liquid-cooled engine uses a pump to circulate coolant as its method of cooling.