Where is the Outer Marker for an instrument landing system located?

The Outer Marker for an Instrument Landing System (ILS) is typically positioned 4 to 7 nautical miles from the runway threshold. This distance allows for effective and timely guidance by providing pilots with a reference point that indicates their proximity to the airport and readiness for the final approach phase of landing. The Outer Marker typically emits a signal that informs pilots when they are approaching the designated point for initiating the final descent and alignment with the runway.

This specific distance range is established to optimize the transition from en-route navigation to the final stages of an approach, enabling pilots to effectively manage their descent profiles and stabilize their approach. The support it provides is crucial for safe landings, particularly in low visibility conditions where precise navigation is paramount.