If IGN L or IGN R is selected and the ENGINE START switch is in FLT, what happens?

If IGN L or IGN R is selected and the ENGINE START switch is in FLT, what happens?

• A. Ignition to both igniters
• B. Ignition to the selected igniter only
• C. No ignition
• D. Auto-restow activated

Answer: (A)

The system is designed for redundancy with two igniters, one on each side. When the engine start switch is in the flight position, the ignition logic energizes both igniters during start to maximize the chance of a reliable ignite in the demanding conditions of in-flight starts. Energizing both provides protection against a single igniter failure and helps ensure the engine starts successfully. So, selecting an ignition side and having the start switch in flight mode results in ignition to both igniters. The other possibilities aren’t consistent with flight-start behavior, where the ignition system is rated to command both plugs rather than just the selected one or doing nothing or performing an unrelated action like auto-restow.

The system is designed for redundancy with two igniters, one on each side. When the engine start switch is in the flight position, the ignition logic energizes both igniters during start to maximize the chance of a reliable ignite in the demanding conditions of in-flight starts. Energizing both provides protection against a single igniter failure and helps ensure the engine starts successfully.

So, selecting an ignition side and having the start switch in flight mode results in ignition to both igniters. The other possibilities aren’t consistent with flight-start behavior, where the ignition system is rated to command both plugs rather than just the selected one or doing nothing or performing an unrelated action like auto-restow.