On runway approach, what does the ILS Localizer indicate?

The ILS (Instrument Landing System) Localizer indicates the deviation left or right of the runway centerline, which is crucial for pilots during their approach to landing. The Localizer provides lateral guidance to ensure the aircraft aligns properly with the runway's centerline. It transmits a signal that creates an imaginary line extending from the approach end of the runway, allowing pilots to determine whether they are on the correct path.

This capability is vital for maintaining safety during the landing phase, especially in poor visibility conditions where visual cues may be limited. By following the guidance provided by the Localizer, pilots can make necessary adjustments to their flight path to align accurately with the runway, enhancing the precision of the landing procedure.