What must be indicated for the FMS to be valid for instrument approaches?

For the FMS (Flight Management System) to be valid for instrument approaches, it is essential that specific FMS annunciators are displayed correctly. These annunciators provide critical information regarding the operational status of the FMS and its readiness for approaches. Indicators such as "Approach Mode," "Approach Active," or other related notifications must be confirmed to ensure that the system is functioning as expected for executing a precision approach.

This verification is vital because the FMS plays a central role in navigation and approach guidance. If the requisite annunciators are not displayed, this may indicate that the system is not synchronized properly with the required approach procedures, which could lead to navigation errors or inability to capture the correct approach path.

Other factors, such as weather conditions, pilot experience level, or air traffic control clearance, although important in the overall context of flight operations, do not specifically pertain to the validity of the FMS for instrument approaches. Thus, the correct display of FMS annunciators is the crucial requirement.