Which of the following is NOT a primary component of the ILS?

The reason that a VOR transmitter is not considered a primary component of the Instrument Landing System (ILS) stems from the specific functions and roles of the ILS components.

The ILS is designed to assist pilots in landing an aircraft by providing them with lateral and vertical guidance during the approach phase. The primary components of the ILS are the localizer and the glideslope. The localizer provides horizontal guidance to align the aircraft with the runway centerline, while the glideslope offers vertical guidance, helping pilots maintain the correct descent angle toward the runway.

Marker beacons are also part of the ILS system, serving as additional navigational aids that provide information to pilots about their position along the approach path. They help in noting specific points during the approach, such as the Outer, Middle, and Inner markers.

In contrast, a VOR (VHF Omnidirectional Range) transmitter is part of the VOR navigation system, which serves a different purpose in en-route navigation rather than the precision landing provided by ILS components. While VORs are valuable for navigation, they do not contribute to the landing guidance that the ILS is specifically designed for. Thus, identifying the VOR transmitter as not a primary ILS component is