Definition
An Instrument Landing System approach that has Distance Measuring Equipment co-located with the localizer, allowing the pilot to determine precise distance from the runway threshold throughout the approach. The DME signal is transmitted on a frequency paired with the ILS localizer frequency, so tuning the ILS automatically tunes the associated DME.
Plain English
An ILS approach that also gives you a continuous readout of how far you are from the runway, using equipment paired with the localizer.
Context Anchor
Seen on instrument approach charts and in instrument flying discussions when an ILS approach also uses DME distance information.
Why Pilots Care
Gives pilots precise distance to the runway during an ILS approach, allowing accurate timing of descent steps and decision height calls.
Intuition Check
Do not read ILS/DME as one single guidance signal. The ILS gives path guidance; the DME adds distance information.
Example Sentence 1
Cleared for the ILS/DME Runway 27 approach, the pilot crossed the final approach fix at 4.2 DME and began the descent.
Example Sentence 2
During the approach briefing, the crew noted the ILS/DME would provide range information past the final approach fix.