Plain English Meaning

The collection of equipment and procedures that lets a pilot fly down to a runway safely when they cannot see the ground because of clouds or low visibility. Each system gives the pilot directional and sometimes vertical guidance until they are close enough to land.

Full Definition

Ground-based and satellite-based navigation systems that guide an aircraft from the en route environment down to a point near the runway from which a landing can be made under instrument flight rules. These systems include precision approaches such as the Instrument Landing System (), nonprecision such as , , and , and approaches using and , each defined by with specified , , and .