What does the outer marker beacon indicate, including its color?

The outer marker beacon indicates the position of the aircraft as it approaches the final approach segment of a precision approach, specifically for an Instrument Landing System (ILS) approach. It typically signals the point where the aircraft should be at or below a specific altitude, aiding in the monitoring of the approach.

The outer marker beacon is color-coded to signify its purpose, and in this case, it emits a blue light. The blue color is associated with the glide slope intercept, indicating that the aircraft is at the correct altitude for an optimal approach path. This is crucial for pilots, as it indicates that they should be preparing for the descent to meet the glide slope and successfully complete the approach to the runway.

The significance of the blue beacon is not just in its color but also in its function as part of the guidance system that helps ensure a safe and precise landing. This understanding reinforces the importance of the outer marker in conjunction with other navigational aids during an instrument approach.