Which data is essential for RNAV navigation to function via an FMS?

• A. Pilot-defined headings only.
• B. Ground-based VOR signals only.
• C. Database of waypoints and procedures.
• D. Visual cues only.

Answer: (C)

RNAV navigation via an FMS relies on a navigation database that contains waypoints, routes, and published procedures (such as SIDs, STARs, and approaches). The FMS uses this data to plan a flight path and generate automatic lateral and vertical guidance, typically using position information from GNSS to follow that defined route. Without a current, accurate database, there’s no defined sequence of waypoints or procedures for the FMS to follow, so RNAV routing cannot function. Pilot-defined headings alone don’t specify a path, ground-based VOR signals don’t provide the RNAV route data, and visual cues aren’t used by the FMS to navigate RNAV paths.