Number of Igniters in a high-bypass turbofan jet engine

 A high-bypass turbofan jet engine typically uses two igniter plugs (called spark plugs in automotive terms) per engine. These igniter plugs are part of the engine’s ignition system and are located in the combustion chamber, providing the initial spark to ignite the fuel-air mixture during engine startup.

Key Points:

• Number of Igniters: Usually two per engine (some older or specialized engines may have more).
• Purpose: Used primarily during engine startup and occasionally for in-flight relight if necessary.
• Continuous Ignition: In some situations (such as turbulence, icing conditions, or heavy rain), continuous ignition may be required to prevent flameout.

Unlike car engines, jet engines rely on continuous combustion after ignition, meaning they do not need spark plugs firing repeatedly during operation.