Instrument Landing System
From Wikipedia, the free encyclopedia.

Instrument Landing System, ILS is an air navigation system for landing.

Components:

Localiser (horizontal position relative to runway centreline) -- broadcast from beyond the far end of the runway from a horizontal array of antenna

Glideslope (vertical positition relative to the ideal approach) -- broadcast from the side of the runway

The original article can be found at: http://en.wikipedia.org/wiki/Instrument_Landing_System.
All text is available under the terms of the GNU Free Documentation License.