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Aviation glossary

Distance Measuring Equipment

What is distance measuring equipment?

FAA handbook figure illustrating distance measuring equipment

Distance Measuring Equipment (DME) is a pulse-type electronic navigation system that displays, on a cockpit instrument, the number of nautical miles between your aircraft and a ground station or waypoint. The aircraft transmits interrogating radio frequency (RF) pulses to the ground facility, which replies, allowing the receiver to compute distance. When paired with a VOR, DME lets you pin down an exact position using both bearing and distance to or from the station. Think of it as your "how far away am I?" readout—just remember it shows slant-range distance, not horizontal distance over the ground.

Also known as: DME, distance measuring equipment

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