What is the normal starting sequence for the turbine engine fuel system?

What is the normal starting sequence for the turbine engine fuel system?

• A. Rotate the compressor with the starter; turn ignition on; open the engine fuel valve (to idle) via throttle or switch.
• B. Move throttle to idle; rotate the compressor with the starter; turn ignition on.
• C. Turn ignition on; rotate the compressor with the starter; and open the engine fuel valve.
• D. Rotate the compressor with the starter; turn ignition on; open the engine fuel valve.

Answer: (D)

Starting a turbine engine properly begins with bringing the compressor up to speed using the starter. This creates the necessary airflow for combustion. Next, energize the ignition system so a flame is ready to start as soon as fuel is introduced. Only after ignition is armed should fuel be supplied to the combustor by opening the engine fuel valve. Supplying fuel before the ignition is ready can allow fuel to flow without a flame, risking a hard start or fuel leakage issues, while lighting the flame before airflow is established can also cause unstable starting. Once light-off is achieved, the engine is brought to idle by controlling fuel flow and throttle as needed. This order—spool, ignition, then fuel—ensures a safe, controlled light-off and smooth transition to idle.

Starting a turbine engine properly begins with bringing the compressor up to speed using the starter. This creates the necessary airflow for combustion. Next, energize the ignition system so a flame is ready to start as soon as fuel is introduced. Only after ignition is armed should fuel be supplied to the combustor by opening the engine fuel valve. Supplying fuel before the ignition is ready can allow fuel to flow without a flame, risking a hard start or fuel leakage issues, while lighting the flame before airflow is established can also cause unstable starting. Once light-off is achieved, the engine is brought to idle by controlling fuel flow and throttle as needed. This order—spool, ignition, then fuel—ensures a safe, controlled light-off and smooth transition to idle.