Marker beacons indicate both aurally and visually when the aircraft is directly over the facility.

• A. True
• B. False
• C. Only audio
• D. Only visual

Answer: (A)

Marker beacons give you two kinds of cues to confirm you’re on the correct approach: an audible tone and a visual light indicator. Each marker on an ILS has a color and a tone that identifies its position along the approach path—outer marker (blue light, 400 Hz tone), middle marker (amber light, 1300 Hz tone), and inner marker (white light, 3000 Hz tone). When you fly over the beacon, the marker receiver in the cockpit both lights up the appropriate color and plays the corresponding tone, giving you simultaneous visual and aural confirmation of your position. That combination of cues is why the statement is true. You don’t rely on just one sense—the system is designed to provide both so you can verify your location on the approach, especially as you approach the runway.