Definition
A position fix determined by measuring the slant-range distance from two separate DME (Distance Measuring Equipment) ground stations simultaneously. The aircraft's position is established at the point where the two distance arcs intersect, providing a reliable fix without needing a VOR bearing.
Plain English
A way of pinpointing where the aircraft is by measuring how far it is from two different ground stations at the same time. Where those two distances cross is your location.
Context Anchor
Seen in instrument navigation, especially when discussing DME errors, area navigation systems, and how an aircraft position is calculated without using only one station.
Derivation
DME stands for Distance Measuring Equipment. The 'DME/DME' construction simply means 'two DMEs working together.' Naming it this way distinguishes it from a VOR/DME fix, where one distance is paired with one bearing instead.
Why Pilots Care
Provides a reliable position fix when GPS is unavailable or when cross-checking other navigation sources.
Analogy
It is like finding your location on a map by knowing you are 8 miles from one town and 12 miles from another. Where those two distance circles meet is your likely position.
Intuition Check
Do not read fix as repair. In aviation navigation, a fix means a known position, not something being corrected or repaired.
Example Sentence 1
When GPS coverage was lost, the flight management system reverted to a DME/DME fix to maintain accurate navigation along the route.
Example Sentence 2
ATC cleared the flight direct to the DME/DME fix 12 miles east of the VOR.