Definition
An RNAV path and terminator leg type (CF, or Course to Fix) that follows a localizer course on its south-facing alignment, used in coded instrument procedure data to guide the aircraft along the localizer signal toward a defined fix. It is the localizer course flown when the procedure is oriented to the south, as opposed to the north course of the same localizer.
Plain English
It is the south-pointing side of a localizer beam, used in a coded flight procedure to guide the aircraft along that beam to a specific point.
Context Anchor
Seen in instrument procedure descriptions and path-leg coding when a procedure tells the aircraft or pilot to intercept or follow a specific localizer course.
Derivation
Localizer comes from 'localize' -- to pinpoint a location -- because the signal narrows the aircraft onto a precise lateral path. 'South course' simply identifies which direction along that path the aircraft is flying.
Why Pilots Care
Correct identification prevents lateral deviation and ensures safe alignment with the runway centerline in instrument conditions.
Grounding Statement
Picture an invisible straight line made by radio signals, marked as the south course, that the aircraft can join and follow.
Intuition Check
South does not mean “any route generally going south.” Here it identifies a specific published localizer path. Course does not mean a class or lesson; here it means the path the aircraft is meant to follow.
Example Sentence 1
The procedure coding called for the aircraft to intercept and track the localizer south course to the final approach fix.
Example Sentence 2
On the missed approach the pilot tracked the localizer south course outbound until reaching the holding fix.