What is the purpose of an instrument landing system (ILS)?

The purpose of an instrument landing system (ILS) is to provide precision guidance for landing. This system consists of two main components: a localizer and a glide slope. The localizer provides lateral guidance to ensure the aircraft is aligned with the centerline of the runway, while the glide slope offers vertical guidance, helping pilots maintain the correct descent path during the approach. The ILS is critical for enabling safe landings in low visibility conditions, allowing pilots to execute precise approaches and landings with a high degree of accuracy.

While enhancing autopilot functions is a benefit of using an ILS, it is not the primary purpose of the system. Similarly, calculating weight and balance or monitoring fuel consumption are important aspects of flight operations, but they are unrelated to the actual function of the ILS in assisting with landings. Thus, providing precision guidance during the landing process is the essence of what the ILS is designed to accomplish.