Plain English Meaning
A landing aid that uses microwave radio signals to guide an aircraft to the runway, telling the pilot exactly where they are left-or-right, up-or-down, and how far out they are.
Full Definition
A precision approach and landing guidance system that uses microwave signals to provide pilots with accurate azimuth (lateral), elevation (vertical), and range information during the final approach to a runway. MLS was developed as a more flexible alternative to the Instrument Landing System (ILS), allowing curved and segmented paths in to .