What is the role of the ignition system in a gas turbine?

• A. To ignite the fuel-air mixture during start and, if required, relight after a flameout.
• B. To regulate fuel temperature.
• C. To provide cooling to turbine surfaces.
• D. To measure exhaust gas temperature.

Answer: (A)

Ignition systems provide the energy to light the fuel-air mixture in the combustor, enabling the engine to start. They deliver a spark or hot flame during start and stay ready to relight if the flame goes out, so the engine can recover without manual intervention. This ignition role is controlled by the start system and is often designed with redundancy (two igniters) to ensure reliable light-off under different conditions. This function is distinct from regulating fuel temperature, cooling turbine surfaces, or measuring exhaust gas temperature, which are handled by other subsystems.