What does "range" refer to in navigation?

"Range" in navigation specifically refers to the distance from an aircraft to a navigation facility. This terminology is often used in various contexts, such as when using radio navigation aids. For example, when determining how far an aircraft is from a VOR (VHF Omnidirectional Range) station, pilots consider the range as the straight-line distance to that navigation aid. This measurement is crucial for efficient navigation, especially during approaches and in air traffic management, as it helps pilots understand their proximity to navigational aids, allowing for better planning of flight paths and altitude adjustments.

The other options do not define "range" accurately in the context of navigation. For example, the time taken to complete a flight is more related to flight duration, while altitude refers to how high an aircraft is flying. The direction of flight relative to true north relates to heading or course, not range. Thus, understanding "range" as the distance to a navigation aid is vital for safe and effective flight operations.