An instrument landing system (ILS) is a ground-based instrument approach system that provides precision guidance to an aircraft approaching and landing on a runway, using a combination of radio signals and, in many cases, high-intensity lighting arrays to enable a safe landing during instrument meteorological conditions (IMC), such as low ceilings or reduced visibility due to fog, rain, or blowing snow.
Instrument approach procedure charts (or approach plates) are published for each ILS approach, providing pilots with the needed information to fly an ILS approach during instrument flight rules (IFR) operations, including the radio frequencies used by the ILS components or navaids and the minimum visibility requirements prescribed for the specific approach.
Radio-navigation aids must keep a certain degree of accuracy (set by international standards of CAST/ICAO); to assure this is the case, flight inspection organizations periodically check critical parameters with properly equipped aircraft to calibrate and certify ILS precision.
Read more about Instrument Landing System: Principle of Operation, Use, ILS Categories, Limitations and Alternatives, History, Future, Frequency List
Famous quotes containing the words instrument, landing and/or system:
“A poet is a combination of an instrument and a human being in one person, with the former gradually taking over the latter. The sensation of this takeover is responsible for timbre; the realization of it, for destiny.”
—Joseph Brodsky (b. 1940)
“I foresee the time when the painter will paint that scene, no longer going to Rome for a subject; the poet will sing it; the historian record it; and, with the Landing of the Pilgrims and the Declaration of Independence, it will be the ornament of some future national gallery, when at least the present form of slavery shall be no more here. We shall then be at liberty to weep for Captain Brown. Then, and not till then, we will take our revenge.”
—Henry David Thoreau (1817–1862)
“Ethics and religion differ herein; that the one is the system of human duties commencing from man; the other, from God. Religion includes the personality of God; Ethics does not.”
—Ralph Waldo Emerson (1803–1882)