Which action yields entry into hard alternate mode?

Which action yields entry into hard alternate mode?

• A. Retarding the thrust lever to idle
• B. Advancing the thrust lever to maximum
• C. Moving the start lever to OFF
• D. Engaging auto-relight

Answer: (A)

Entering hard alternate mode is triggered by bringing the thrust lever to idle, because this signals the engine control to exit the normal high‑power startup path and hand control over to the backup/alternate system. With the engine demand reduced to idle, the primary control logic stops trying to manage high thrust and the alternate ignition/fuel control path can take over, allowing operation under hard alternate conditions. Pushing the thrust lever to maximum keeps the normal control path active and does not initiate the alternate mode. Moving the start lever to OFF ends the start sequence rather than switching to alternate control. Engaging auto-relight targets restoring ignition under normal control rather than invoking the alternate mode.

Entering hard alternate mode is triggered by bringing the thrust lever to idle, because this signals the engine control to exit the normal high‑power startup path and hand control over to the backup/alternate system. With the engine demand reduced to idle, the primary control logic stops trying to manage high thrust and the alternate ignition/fuel control path can take over, allowing operation under hard alternate conditions. Pushing the thrust lever to maximum keeps the normal control path active and does not initiate the alternate mode. Moving the start lever to OFF ends the start sequence rather than switching to alternate control. Engaging auto-relight targets restoring ignition under normal control rather than invoking the alternate mode.