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instrument landing system

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Also known as ILS

ground-based visual aid for landing

Wikidata facts

Instance of
system
Image
Lumières et ILS de la piste 06 L (3083202657).jpg
Show 3 more facts
Commons category
Instrument landing systems
short name
ILS
Sources (1)

via Wikidata · CC0

~40 min read

Encyclopedic overview

Diagram of an instrument landing system (ILS) approach

In aviation, the instrument landing system (ILS) is a precision radio navigation system that provides short-range guidance to aircraft to allow them to approach a runway at night or in bad weather. In its original form, it allows a pilot, through a cockpit mounted instrument in the aircraft that displays lateral and vertical guidance indications (needles),, to approach until the aircraft is 200 feet (61 m) over the ground, within 1⁄2 mile (800 m) of the runway. At that point the runway should be visible to the pilot; if it is not, they perform a missed approach. Bringing the aircraft this close to the runway dramatically increases the range of weather conditions in which a safe landing can be made. Other versions of the system, or "categories", have further reduced the minimum altitudes, runway visual ranges (RVRs), and transmitter and monitoring configurations designed depending on the normal expected weather patterns and airport safety requirements.

Excerpted from Wikipedia’s “instrument landing system” article, available under the CC BY-SA 4.0 licence.