When does the SPDS enter failsafe mode?

The SPDS enters failsafe mode when the SPDS CDU has lost communication. This is an essential function designed to maintain safety and reliability in the event of communication loss. Failsafe mode ensures that the system can revert to a basic operational state to prevent potential risks or hazards that could arise from a loss of data flow. This mode is crucial for continued safe monitoring of the aircraft's status, as it provides the opportunity to minimize the impact of any critical failures associated with lost communications.

Understanding this helps reinforce the significance of maintaining communication channels in aerospace systems, as the health and operability of such systems often rely heavily on continuous data exchange.