ILS stands for Instrument Landing System, which is a precision radio navigation system used in aviation. It provides short-range guidance to aircraft to help pilots approach and land on a runway, especially under low visibility conditions such as night, fog, rain, or snow. The ILS system offers two main types of guidance:
- Horizontal guidance via the localizer, which sends signals to help pilots stay aligned with the runway centerline.
- Vertical guidance via the glideslope, which provides the correct descent angle to the runway.
There are additional components like distance measuring equipment or marker beacons to provide distance information to the runway. ILS is critical for safe landings when visual reference to the runway is limited or unavailable, allowing pilots to safely land when they cannot see the runway until they are very close. Some advanced ILS categories allow pilots to land automatically without visual contact.
