How ILS Works | Instrument Landing System Explained | IFR Training

An introduction to how the Instrument Landing System (ILS) works. When visibility is too poor to allow for a visual approach to a runway, aircraft use instruments to detect radio signals aligning them with the centerline and proper approach path. Complete Your IFR Training! Visit for the FlightInsight Ground School! The oldest and still most precise form of instrument approach is the ILS. It involves a glideslope antenna, transmitting a signal giving the aircraft vertical guidance, and a localizer, giving lateral guidance. It can also provide distance information using marker beacons. By following these signals, aircraft can descend to almost the runway threshold before gaining visual sight of the field for landing. Here’s a basic explanation of the Instrument Landing System, using an example approach at Sioux Falls, IA. If you’re enjoying this content please consider supporting us on Patreon at Thanks to Global Life for the clip at the beginning of this video of an ILS approach to landing at minimums: