back course

back course

[′bak ‚kȯrs] (navigation) In the instrument low-approach system, the course which extends from the back of a localizer antenna system to furnish guidance in the horizontal plane at the rear of the localizer.

back course

The course line along the extended centerline of a runway in the opposite direction to the front course, or the localizer course for an ILS (instrument landing system). For an aircraft to approach the instrument runway from the end on which the localizer antenna is installed, the back course must be flown. A localizer back course is shown as on aeronautical charts. The sector located on the opposite side of the localizer from the runway is called the back course sector.