Instrument Rating Checkride Practice Test

The color white is specifically used to identify the Back Course Marker. This marker is part of the instrument landing system (ILS) used during the approach to a runway when flying the back course of a localizer approach. The back course marker helps pilots maintain awareness of their position in relation to the glide slope as they navigate from the opposite direction of the regular localizer approach.

In contrast, the other markers—Outer, Middle, and Inner—are typically associated with specific phases of an approach but are not characterized by the color white. The Outer Marker, for example, is often depicted in blue, while the Middle and Inner Markers can be associated with other colors such as amber or yellow. Therefore, recognizing that the Back Course Marker is distinguished by its white color is essential for understanding its role in instrument approaches and ensuring the correct identification of navigational aids in the cockpit.