Definition
A cockpit instrument that displays the pressure of the engine's lubricating oil, typically in pounds per square inch (psi). It provides a real-time reading from a sensor in the engine's oil system, allowing the pilot to confirm that oil is circulating at the correct pressure to lubricate and cool internal engine components.
Plain English
A gauge in the cockpit that shows whether the engine is getting oil at the right pressure. If the needle is in the normal range, the engine is being properly lubricated. If it drops, something is wrong.
Context Anchor
Seen on the instrument panel during engine start, including hand propping, and checked again during normal engine operation.
Derivation
Indicator comes from Latin indicare, meaning to point out or make known. That fits this instrument because it points out the condition of the engine's oil pressure instead of leaving the pilot to guess.
Why Pilots Care
Low or zero oil pressure can signal a pump failure, leak, or blockage that will rapidly damage the engine if not corrected.
Intuition Check
Do not confuse the oil pressure indicator with an oil quantity check. It shows oil pressure while the engine is running; it does not tell you how much oil is in the engine.
Example Sentence 1
After starting the engine, the pilot watched the oil pressure indicator and confirmed the needle moved into the green arc within 30 seconds.
Example Sentence 2
A sudden drop on the oil pressure indicator during cruise requires an immediate precautionary landing.