Microwave landing system (MLS)

Article By:

Vickers, Douglas B. Avionics Engineering Center, Ohio University, Athens, Ohio.

DiBenedetto, Michael F. Avionics Engineering Center, Ohio University, Albany, Ohio.

Last reviewed:January 2020

DOI:https://doi.org/10.1036/1097-8542.424150

An all-weather aircraft landing-guidance system that operates at microwave frequencies and provides deviations from the landing runway centerline using a time-referenced scanning beam (TRSB) technique. The MLS was standardized in 1988 and approved for use in international civil aviation until at least the year 2020. MLS is used to support low-visibility instrument precision approach and landing operations in North America and Europe. In addition to the fixed-base MLS equipment design, a compact mobile microwave landing system (MMLS) equipment design exists. The instrument landing system (ILS) is also standardized internationally and approved for use indefinitely as countries implement their transition to new technologies. Standards for a third landing system, the Global Navigation Satellite System (GNSS), based primarily on Global Positioning System (GPS) technology, exist. Multimode receivers enable an aircraft to conduct an instrument approach using ILS, MLS, or GNSS. See also: Instrument landing system (ILS); Satellite navigation systems

The content above is only an excerpt.