Which mode is used for lateral navigation during an ILS approach?

The lateral navigation during an Instrument Landing System (ILS) approach is managed using the localizer mode, which is represented by LOC mode. The localizer provides precise lateral guidance to the runway centerline, allowing the pilot to align the aircraft with the runway during the final approach. By utilizing LOC mode, the aircraft receives signals transmitted from the ground-based localizer, ensuring that the aircraft maintains the correct heading as it descends toward the runway.

Other modes, such as vertical speed (VS mode) and lateral navigation (LNAV mode), serve different purposes. VS mode is focused on controlling the vertical speed of the aircraft, not managing lateral movement, while LNAV mode is typically used for lateral navigation with waypoints in predefined flight paths and does not provide the specific guidance needed during an ILS approach. VGP mode, which relates to vertical guidance in certain advanced systems, also does not apply directly to lateral navigation for ILS. Therefore, LOC mode is distinctly suited for the lateral navigation requirements during an ILS approach.