Which are components of the ILS system?

• A. Localizer, Glideslope, Marker Beacons
• B. Localizer, Marker Beacons
• C. Glideslope, Marker Beacons
• D. Localizer, Glideslope

Answer: (A)

The system uses three main subsystems to guide you to a runway: a localizer for horizontal guidance to the runway centerline, a glideslope for vertical guidance on the correct descent path, and marker beacons that provide position cues along the approach (outer, middle, and sometimes inner markers). The localizer tells you left or right to stay on the centerline, while the glideslope tells you whether you’re on the proper descent angle toward the runway. Marker beacons give precise checkpoints along the approach and audible/visual cues to confirm your position as you near the runway. Because all three elements work together to provide complete lateral, vertical, and situational guidance, this combination is the correct representation of the ILS components.