What is the primary purpose of a VOR in the context of navigation?

The primary purpose of a VOR (VHF Omnidirectional Range) is to provide radial information for aircraft navigation. VOR is a type of radio navigation system that allows pilots to determine their position and stay on course by providing azimuth (radial) information. When a pilot tunes into a VOR station, the aircraft's navigation system can calculate the current heading in relation to the station, enabling the pilot to navigate along specific flight paths or radials.

This system is particularly useful as it transmits signals in all directions, allowing pilots to use the VOR from various angles to navigate accurately. By understanding which radial they are on in relation to the VOR station, pilots can create a mental map of their position and make informed decisions about their flight path.

Other options, while relevant to aviation, do not capture the primary function of a VOR. The VOR is not designed to facilitate ATC communication, display altitude data, or monitor fuel efficiency, which are addressed by other systems and instruments in the aircraft.