What nonprecision approach makes use of only the localizer component of an ILS system?

The nonprecision approach that utilizes only the localizer component of an Instrument Landing System (ILS) is known as the LOC approach. The localizer provides horizontal guidance to the pilot, directing the aircraft to align with the runway's centerline. Unlike a full ILS approach, which includes both localizer and glide slope components to provide vertical and horizontal guidance for precision landings, the LOC approach does not provide vertical flight path information, making it a nonprecision approach.

In contrast, the ILS approach makes use of both localizer and glide slope elements. The VOR (VHF Omnidirectional Range) approach relies on VOR navigation aids for guidance but doesn't incorporate the localizer of an ILS. Similarly, the NDB (Non-Directional Beacon) approach uses ADF (Automatic Direction Finder) technology and is based on receiving signals from non-directional beacons rather than using any ILS components. Thus, the LOC approach stands out as the specific option that focuses solely on utilizing the localizer aspect of an ILS.