Definition
The localizer signal radiated from the approach end of the runway, providing lateral guidance to aircraft flying inbound toward the runway on the published ILS or LOC approach. The front course is the primary, designed direction of the localizer and is what the approach chart depicts.
Plain English
The normal direction of the runway's lateral guidance signal — the one you fly toward to line up with the runway for landing.
Context Anchor
Seen in ILS and localizer approach discussions, especially when distinguishing the normal approach path from a back course.
Derivation
Course' comes from the Latin cursus, meaning 'a running' or 'path traveled.' 'Front' here means the principal or designed direction — the side the localizer is built to serve. So 'front course' simply means the main published path the signal provides.
Why Pilots Care
Flying the front course delivers the intended guidance; using the opposite signal produces reversed needle indications and unsafe alignment.
Grounding Statement
Picture the runway centerline continuing straight out beyond the runway toward arriving aircraft; that extended path is the front course.
Intuition Check
Front does not mean the front of the airplane. Here, front means the normal approach side of the localizer signal—the side used to fly inbound toward the runway.
Example Sentence 1
Cleared for the ILS Runway 27 approach, the pilot intercepted the front course and tracked it inbound to the runway.
Example Sentence 2
ATC cleared the aircraft to join the front course of the ILS for runway 27.