Definition
A heat exchanger in the engine's lubrication system that removes heat from the circulating engine oil by passing it through a finned core exposed to outside air, keeping oil temperature within operating limits.
Plain English
A small radiator that cools the engine's oil. As oil flows through it, outside air carries the heat away, stopping the oil from getting too hot.
Context Anchor
Seen in engine cooling discussions, before-flight inspections, and oil temperature monitoring during engine operation.
Why Pilots Care
Overheated oil loses its ability to lubricate properly, leading to increased wear or engine failure if the cooler is blocked or inoperative.
Intuition Check
An oil cooler is not a container for storing oil. It is a part the oil flows through so heat can be carried away.
Example Sentence 1
On a hot summer climb, the pilot watched the oil temperature gauge closely to make sure the oil cooler was keeping things in range.
Example Sentence 2
In hot weather the pilot monitored oil temperature closely to confirm the oil cooler was keeping the oil within limits.