Marker Beacon
What is marker beacon?
A marker beacon is a low-powered ground transmitter that aims a narrow, fan-shaped signal straight up, marking a specific point along an instrument approach (such as the outer or middle marker). As you fly directly over it, your marker beacon receiver triggers a light and audio tone, telling you your position along the final approach course. Set receiver sensitivity to "low" during an approach for the sharpest, most precise indication. Think of it as a vertical "you are here" pin on the approach path.
Also known as: outer marker, middle marker, inner marker, OM, MM, IM
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