Definition
A starting igniter used in some turbine engines that consists of an electrically heated coil, similar to the glow plug in a diesel engine. When energized during the start sequence, the coil heats to a high temperature and ignites the fuel-air mixture in the combustion chamber. Unlike a high-energy spark igniter, a glow-plug igniter ignites the mixture by direct contact with the heated element rather than by an electrical spark.
Plain English
A small electrically heated wire that gets red-hot and lights the fuel in the combustion chamber when the engine is starting. Once the engine is running and the flame is self-sustaining, the igniter is switched off.
Context Anchor
Seen in discussions of small engines, combustion heaters, and ignition systems that use a heated element to start burning.
Derivation
‘Glow plug’ comes from diesel engine terminology, where a heated coil glows red-hot inside the cylinder to warm the air enough for the fuel to ignite. The aviation term borrows the same idea: an element that ignites fuel by glowing rather than by sparking.
Why Pilots Care
Provides reliable starting for glow engines where spark ignition is not used, reducing the chance of a failed start or flooded engine.
Grounding Statement
Picture a small metal element heating up until it glows red, then lighting the fuel mixture when fuel reaches it.
Intuition Check
A glow-plug igniter is not the same as a spark plug. A spark plug fires a spark; a glow-plug igniter lights the mixture with steady heat.
Example Sentence 1
During the start sequence, the glow-plug igniter heats up and lights the fuel-air mixture in the combustion chamber.
Example Sentence 2
Once the engine was running smoothly, the pilot removed the glow-plug igniter and secured it in the cockpit.