During an ILS approach, how does the FMS provide guidance and how does the autopilot interact with the localizer and glideslope?

During an ILS approach, how does the FMS provide guidance and how does the autopilot interact with the localizer and glideslope?

• A. The FMS provides lateral and vertical guidance, and the autopilot captures the localizer and glideslope in approach mode.
• B. The FMS provides lateral guidance only, and the autopilot relies on raw signals to capture the localizer.
• C. The FMS provides vertical guidance only, and the autopilot does not couple to navigation signals.
• D. The FMS has no role in ILS approaches; autopilot handles all signals independently.

Answer: (A)

In an ILS approach, the guidance you follow comes from the combination of the ILS signals and the flight guidance system. The localizer provides the horizontal path toward the runway centerline, while the glideslope provides the vertical descent path. The FMS contributes by planning the approach path and, if flight-director guidance is used, presenting lateral and vertical guidance to steer along that path. When you engage approach mode, the autopilot couples to the navigation signals and automatically captures the localizer for horizontal control and the glideslope for vertical control. Once captured, the autopilot flies the aircraft to stay centered on both cues, following the glidepath down to the runway until landing or decision altitude.

In an ILS approach, the guidance you follow comes from the combination of the ILS signals and the flight guidance system. The localizer provides the horizontal path toward the runway centerline, while the glideslope provides the vertical descent path. The FMS contributes by planning the approach path and, if flight-director guidance is used, presenting lateral and vertical guidance to steer along that path. When you engage approach mode, the autopilot couples to the navigation signals and automatically captures the localizer for horizontal control and the glideslope for vertical control. Once captured, the autopilot flies the aircraft to stay centered on both cues, following the glidepath down to the runway until landing or decision altitude.