What happens in the cockpit when a marker beacon is passed?

• A. The marker beacon indicator light goes out and the audio tone stops
• B. The outer marker light flashes and the inner marker beep increases
• C. The marker beacon resets the autopilot
• D. The marker beacon triggers a display of altitude above runway

Answer: (B)

Marker beacons give you location cues on an ILS approach using distinct lights and tones for each beacon. When you pass the outer marker, the blue indicator light begins to flash, signaling that you’ve crossed that beacon. At the same time, as you continue toward the runway, the inner-marker audio cue becomes more noticeable, helping you gauge your progress along the approach path. This combination of a flashing outer-marker light and an increasing inner-marker tone is how the cockpit cues confirm your position on the final approach. Marker beacons don’t reset the autopilot, they don’t display altitude above the runway, and the indicator doesn’t just extinguish or stop the audio.