What does the middle marker beacon indicate and what is its color?

The middle marker beacon is an important component of the instrument landing system (ILS) that provides pilots with a visual indication of their position during the approach to a runway, specifically during an ILS approach. It is placed at a predetermined point along the approach path, typically located at a distance of approximately 3,500 feet from the runway threshold.

The color associated with the middle marker beacon is amber, and its main purpose is to indicate the decision altitude, which is the altitude at which the pilot must decide whether to continue the approach or execute a missed approach procedure. When the amber light is illuminated, it signals that the aircraft is at the middle marker, and the pilot must prepare to make decisions concerning landing based on visibility and other factors.

Understanding this critical point helps pilots maintain situational awareness during an approach, as it acts as a cue for them to assess whether they are sufficiently aligned and configured for landing. The middle marker beacon plays a vital role in ensuring safe and effective landings, particularly in low visibility conditions.