Definition
A non-precision instrument approach that uses a localizer for lateral (left/right) guidance to the runway and DME (Distance Measuring Equipment) to identify fixes, step-down points, and the missed approach point along the final approach course. It does not provide vertical (glideslope) guidance, so the pilot descends through published step-down altitudes based on DME distances.
Plain English
An approach where one signal keeps you lined up with the runway and a distance reading tells you how far you are from it. You step down to lower altitudes at specific distances rather than following a glideslope down.
Context Anchor
Seen on instrument approach charts and used while flying an approach in clouds or low visibility when runway alignment and distance information are needed.
Derivation
Localizer comes from the idea of “localizing,” or placing the aircraft on the correct runway-aligned course. DME stands for distance measuring equipment, which describes its job: giving the pilot distance information during the approach.
Why Pilots Care
Provides accurate distance information that lets pilots manage altitude and timing without needing a full ILS or timing from the final approach fix.
Intuition Check
Do not assume “localizer/DME” means the same thing as an ILS. The localizer gives left-right alignment, and the DME gives distance; they do not automatically give a glidepath down to the runway.
Example Sentence 1
With the glideslope out of service, the crew briefed the localizer/DME approach and reviewed the step-down altitudes for each DME fix.
Example Sentence 2
After receiving the approach clearance, the crew monitored DME to identify the step-down fixes on the localizer/DME approach plate.