The DME's signal is used to determine distance. Pilots can then use this information, usually shown by the transponder in the form of tenths of a nautical mile, to plot the path of the airplane. Sometimes DME equipment is paired with VOR stations. Most pilots are now familiar with GPS or a global positioning system.

A pilot knows the route through a process called flight planning, which begins hours before takeoff. This plan is not a "straight line" but a series of waypoints—specific GPS coordinates or radio navigation beacons—that form an invisible highway in the sky. These routes are pre-calculated by the airline's dispatchers to account for weather, fuel efficiency, and air traffic control (ATC) restrictions. Once in the cockpit, the pilot enters this flight plan into the Flight Management System (FMS), which displays the path on the navigation screens. During the flight, the pilot follows the route using a combination of satellite GPS (GNSS) and ground-based radio signals like VOR (VHF Omnidirectional Range). In 2026, most modern aircraft use RNAV (Area Navigation), allowing them to fly direct paths between any two points on the globe. Throughout the journey, pilots stay in constant contact with ATC, who may provide "vectors" (turn instructions) to avoid other aircraft or bad weather, ensuring the plane stays on its assigned "track" with pinpoint accuracy.