Which components are part of the ILS system?

The ILS (Instrument Landing System) is a precision approach system that provides accurate guidance to aircraft during the landing phase. The key components of an ILS consist of a localizer, which provides horizontal guidance to align the aircraft with the runway centerline, and a glideslope, which offers vertical guidance to help the pilot maintain the correct descent path to the runway. Marker beacons are in place to alert pilots when they are passing specific points along the approach path, providing additional situational awareness.

This answer is correct because these three components—localizer, glideslope, and marker beacons—work together to create a cohesive system that aids pilots in landing, particularly in low visibility conditions. Each component plays a crucial role: the localizer ensures lateral alignment, the glideslope monitors the right descent angle, and marker beacons indicate key points on the approach.

In contrast, other options introduce components that either fall outside the standard ILS system or do not perform the same functions. For instance, DME (Distance Measuring Equipment) and RNAV (Area Navigation) are not part of the ILS framework, as they serve different navigational purposes. Similarly, VOR (VHF Omnidirectional Range) and TACAN (