Instrument Flying Handbook Practice Test

The main idea is how to read a front course localizer depiction: the shaded side of the arrowhead shows the front course. The localizer can be viewed from the front or rear, but only the front course is used for the inbound path to the runway. By convention, the side of the arrowhead that is shaded indicates the front course, so when the right side is shaded, it means the usable front course lies to the right of the line. This shading provides a quick, visual cue to distinguish the front course from the rear course (which would be on the opposite, unshaded side).