Definition
A method of separating aircraft in the same airspace by using distance measurements from a Distance Measuring Equipment (DME) station, expressed in nautical miles. Air traffic control issues clearances that keep aircraft a specified DME distance apart along a route or radial.
Plain English
Keeping aircraft a safe distance apart by measuring how far each one is from the same ground station, using the distance readout in the cockpit.
Context Anchor
Used in air traffic control, especially when aircraft are navigating by distances from a DME-equipped station.
Derivation
DME stands for Distance Measuring Equipment, a system that tells the pilot how far the aircraft is from a ground station in nautical miles. 'Separation' here means the spacing ATC keeps between aircraft to prevent conflict. Combined, it means spacing aircraft by their DME distance readings.
Why Pilots Care
Allows safe aircraft spacing in non-radar environments or when tighter control is needed, reducing the risk of mid-air conflict.
Intuition Check
Do not read “separation” here as just a general idea of being apart. In ATC, separation means required spacing that must be maintained using an approved method.
Example Sentence 1
Center cleared us to maintain 20 miles DME separation from the preceding traffic on the same airway.
Example Sentence 2
DME separation was used during the approach because radar was unavailable in that sector.