Glideslope

(See also Instrument Landing System, Intercept Glideslope Altitude, Localizer, Middle Marker, Outer Marker) Provides vertical guidance for aircraft during approach and landing. The glideslope/glidepath is based on the following: 1) Electronic components emitting signals which provide vertical guidance by reference to airborne instruments during instrument approaches such as Instrument Landing System (ILS)/Microwave Landing System (MLS), or 2) Visual ground aids, such as Visual Approach Slope Indicator (VASI), which provide vertical guidance for a Visual Flight Rules (VFR) approach or for the visual portion of an instrument approach and landing or 3) Used by Air Traffic Control (ATC) to inform an aircraft making a Precision Approach Radar (PAR) approach of its vertical position (elevation) relative to the descent profile. (FAA4)