Definition
An instrument approach procedure that uses a localizer for lateral (left/right) guidance to the runway, paired with DME to provide continuous slant-range distance information from a designated DME station. Unlike a full ILS, a LOC/DME approach provides no electronic glideslope, so it is flown as a non-precision approach using step-down altitudes referenced to DME distances.
Plain English
An approach that gives you a radio beam to keep you lined up with the runway, plus a distance readout telling you how far you are from a fixed point. You use the distance to know when to step down to lower altitudes, because there's no electronic up-and-down guidance.
Context Anchor
Seen on instrument approach charts, especially in the plan view and facility information for a localizer-based approach.
Derivation
Localizer comes from the idea of localizing — pinpointing — your position left or right of the runway centerline. DME (Distance Measuring Equipment) measures distance by timing a radio signal sent to a ground station and back. The slash simply pairs the two systems used together on this approach.
Why Pilots Care
Gives pilots exact distances to step-down fixes and the missed approach point without needing additional navigation aids.
Intuition Check
Do not read LOC/DME as just another name for a localizer. The DME part matters because distance information may be required to fly the procedure correctly.
Example Sentence 1
With the glideslope out of service, the crew briefed the LOC/DME approach and set up to use the DME readouts for their step-down altitudes.
Example Sentence 2
The approach plate showed the LOC/DME symbol, confirming distance information would be available on the localizer course.