What does the ST-BY PUMP ON C#1 CAS message indicate?

The indication that the standby pump is connected to hydraulic system 1 is significant for understanding the operational status of the hydraulic systems on the Dassault Falcon 2000LXS. When the ST-BY PUMP ON C#1 CAS message is displayed, it informs the flight crew that the standby pump is actively supplying hydraulic pressure to system 1, which is crucial for maintaining control and functionality if the primary hydraulic system encounters issues.

Given that the standby pump serves as a backup, its activation ensures that hydraulic pressure remains available for critical systems and components even when the primary source is not in operation. This redundancy is vital for flight safety, enabling pilots to maintain control over the aircraft's hydraulic-dependent functions.

The other possible interpretations provided in the question do not accurately reflect the message's meaning. While it's true the standby pump's operation is essential, the specific CAS message does not indicate if the primary hydraulic system has failed or if the standby pump is functioning or not; it simply confirms the connection to hydraulic system 1. This distinction is important for efficient troubleshooting and informed decision-making during flight operations.