Plain English Meaning

Landing approaches that use radio signals to guide the aircraft down a precise path to the runway -- one signal keeps the wings lined up with the runway centerline, and another keeps the aircraft on the correct descent angle. The pilot follows these signals down until they can see the runway and land, or until they reach a set altitude where they must go around if the runway is not in sight.

Full Definition

Precision instrument approach procedures that use the Instrument Landing System to provide pilots with electronic lateral guidance (localizer) and vertical guidance (glide slope) to a specific runway. ILS approaches allow aircraft to descend to a published in , at which the pilot must have the required in sight to to landing or otherwise execute the .