What is the primary function of the Glide Slope in the ILS?

The Glide Slope is a crucial component of the Instrument Landing System (ILS), specifically designed to provide vertical guidance to pilots during the approach phase of landing. Its primary function is to ensure that aircraft maintain the correct descent path towards the runway, helping them to descend at an appropriate angle for a safe approach.

By transmitting a radio signal that indicates the ideal vertical angle, the Glide Slope helps pilots understand how high or low they are relative to the optimal glide path. If the aircraft deviates from this path, the pilot can take corrective actions to maintain alignment with the proper descent slope. This vertical guidance is typically set to a three-degree glide path, which is a standard for most ILS approaches.

The other choices do not accurately describe the primary function of the Glide Slope. For example, while lateral guidance is provided by the Localizer, the Glide Slope itself strictly focuses on vertical descent. Distance to the runway and visualizing the approach path are also functions associated with other systems or aids, but they do not define the specific role of the Glide Slope as part of the ILS.