What is the primary function of Distance Measuring Equipment (DME)?

The primary function of Distance Measuring Equipment (DME) is to indicate the distance from a VOR (VHF Omnidirectional Range) station. DME works by sending out a signal that is received by the aircraft's DME unit, which calculates the distance based on the time it takes for the signals to travel to and from the ground station. This is particularly useful for navigation, as it allows pilots to determine their position relative to navigational aids.

By providing distance information, DME enhances situational awareness during flight, especially in complex airspace where accurate positioning is essential for safe operation. It is commonly used in combination with VOR for more effective navigation, allowing pilots to cross-reference their distance to a VOR station while also determining their bearing.

The other options do not represent the function of DME. For example, DME does not provide heading information or measure altitude; those functions are served by other instruments. Additionally, fuel consumption calculations are unrelated to what DME provides.