Which combination is most likely to provide accurate RNAV position fixes?

The most likely combination to provide accurate RNAV (Area Navigation) position fixes is DME / DME. This method relies on Distance Measuring Equipment, which calculates the aircraft's distance from two or more DME ground stations. By using triangulation techniques from these distances, pilots can determine their precise position in three-dimensional space, which is essential for accurate navigation.

DME / DME is highly effective because it provides precise range information that can be used to calculate the aircraft's position relative to the DME stations. This helps create a reliable and accurate RNAV position fix, particularly when flying in areas where other navigational aids may not be available or reliable.

While other combinations like VOR / DME and VOR / VOR are useful and can provide position fixes, they may not have the same level of accuracy as DME / DME. VORs give azimuth information, which can help determine the aircraft's bearing, but when it comes to establishing an exact position, the DME system's range measurements offer a clearer advantage, as they directly relate to the aircraft's distance from the reference points.