Definition
A small electrical tool used during magneto-to-engine timing to indicate the precise moment the magneto breaker points open. It typically has two leads connected across the points and an indicator (light or buzzer) that changes state at the instant the points break, allowing the technician to align that event with the engine's specified firing position.
Plain English
A simple tool with two wires and a light. The light tells the mechanic the exact moment the magneto is about to fire a spark, so the magneto can be set to fire when the engine piston is in the right position.
Context Anchor
Seen during piston-engine maintenance, especially when checking or setting magneto timing before returning an engine to service.
Derivation
Called a 'timing light' because it indicates the moment (the timing) at which the magneto's internal points open. The light is the visible signal of that event.
Why Pilots Care
Correct ignition timing prevents detonation, ensures full engine power, and avoids costly internal damage.
Intuition Check
A timing light is not just a light for seeing the engine. It is an indicator that shows a specific ignition timing point.
Example Sentence 1
After installing the left magneto, the technician connected the timing light leads to the breaker points and slowly rotated the crankshaft until the light indicated the points had just opened.
Example Sentence 2
After adjusting the magneto, the technician rechecked the timing with the light and confirmed the marks aligned correctly at full advance.