Definition
Cockpit indicator lights, normally red, that illuminate to alert the pilot to a condition requiring immediate attention or corrective action. Warning lights signal the most serious category of annunciation, ranking above caution lights (typically amber) and advisory lights (typically green or white).
Plain English
Red lights on the instrument panel that turn on to tell the pilot something is seriously wrong and needs to be dealt with right away.
Context Anchor
Seen on cockpit panels, especially near system controls or on an alert panel that groups several labeled lights together.
Why Pilots Care
They give immediate visual notice of problems so the pilot can take corrective action before a situation becomes critical.
Analogy
A warning light in an aircraft is like the oil-pressure light in a car, but with higher stakes. It does not explain the whole problem by itself; it tells you to look, identify the condition, and take the proper action.
Intuition Check
Do not assume “warning lights” means any light that is easy to see. In aviation, the phrase usually means lights intended to alert the pilot or crew to a condition that may need action.
Example Sentence 1
When the oil pressure warning light illuminated during climb, the pilot reduced power and prepared for a precautionary landing.
Example Sentence 2
The low-voltage warning light came on, prompting the pilot to reduce electrical load and land at the nearest suitable airport.