In what scenario can the STATUS page be accessed on the lower DU?

The STATUS page on the lower Display Unit (DU) can be accessed during single display operation because this mode allows for the necessary information to be displayed on the available screen. In single display operation, the aircraft's systems are capable of rerouting vital display data to ensure the pilot has ongoing access to important information, including system statuses and alerts, even when only one display is functioning. This functionality is critical for maintaining situational awareness and safety in operational scenarios where the normal multi-display configuration is compromised.

In contexts involving other scenarios, such as low visibility conditions, the STATUS page does not rely on external visibility factors. If the upper DU is inactive, certain limitations may prevent the functionality that allows for accessing the STATUS page under normal dual-display configurations. Immediately after engine start, the system may still be initializing, and some functionalities could be limited due to the engine start sequence not being completed.