What is the purpose of the Instrument Landing System (ILS)?

The purpose of the Instrument Landing System (ILS) is to provide precision navigation and landing assistance to aircraft as they approach and land on a runway. ILS consists of two main components: the localizer, which provides horizontal guidance to align the aircraft with the centerline of the runway, and the glide slope, which provides vertical guidance to ensure that the aircraft descends at the correct angle. This system is crucial in helping pilots execute safe landings, especially in low visibility conditions, such as fog or heavy rain, where visual references may be limited or unavailable.

Other options mentioned do not accurately represent the function of the ILS. Guiding aircraft during taxiing relates to surface movement guidance, indicating runway conditions pertains to advisory information about runway status, and managing air traffic control is a broader function involving airspace management and communication with pilots, which is separate from the specific landing assistance provided by the ILS.