How does ATC separation work?
Air traffic controllers keep aircraft safely apart using separation standards - minimum distances that must be maintained between aircraft at all times. When separation is lost or projected to be lost, it's called a conflict.
Separation standards
Two types of separation are used:
Lateral (horizontal) separation:
- En-route (center): 5 nautical miles
- Terminal (TRACON/approach): 3 nautical miles
Vertical separation:
- 1,000 feet (with RVSM below FL410)
- 2,000 feet above FL410 without RVSM
Aircraft are considered separated if EITHER standard is met. Two aircraft can be 1nm apart laterally as long as they have 1,000ft vertical separation.
How controllers maintain separation
Controllers use several techniques:
- Altitude assignments - climb or descend aircraft to different flight levels
- Heading vectors - turn aircraft to increase lateral spacing
- Speed control - slow trailing aircraft to open gaps
- Holding patterns - delay aircraft at a fix when traffic is too dense
- Sequencing - arrange arrival order for efficient flow to the runway
Conflict alert
Real ATC systems project aircraft positions 2 minutes ahead. When the projection shows two aircraft will lose separation, a Conflict Alert (CA) fires - the data blocks flash red and a tone sounds. The controller must act immediately.
Practice separation in radarcontrol.io
radarcontrol.io simulates realistic separation with:
- WASM-accelerated conflict detection projecting 5 minutes ahead
- Severity classification: critical (< 3nm), warning (< 4nm), caution
- Resolution advisories suggesting climbs, descents, turns, or speed changes
- Scoring penalties for separation violations (-200 points per conflict)
- Real airspace data with realistic traffic flows
You can control aircraft manually with text commands or write JavaScript to automate separation logic.