Definition
The separation of aircraft used when providing air traffic control service without the use of radar or ADS-B surveillance, based instead on aircraft position reports, time, altitude, route, and published procedures.
Plain English
Keeping aircraft safely apart by following set rules and timing — using pilot position reports rather than watching them on a radar screen.
Context Anchor
You may see this term in ICAO material, oceanic or remote-area operations, and ATC discussions where radar or other live tracking is not available or not being used.
Derivation
From 'procedural,' meaning done according to a set procedure. The name highlights that controllers rely on established procedures (assigned altitudes, routes, and timed reports) rather than on a live picture of where each aircraft is.
Why Pilots Care
It allows safe operations where radar coverage does not exist, such as over oceans or remote regions.
Analogy
It is like scheduling trains on the same rail system by timetable and track assignment rather than by watching each train live on a map.
Intuition Check
Do not read “procedural” as just paperwork or bureaucracy. Here it means aircraft spacing is maintained by approved control methods instead of continuous live surveillance.
Example Sentence 1
Crossing the North Atlantic, the crew operated under procedural separation and made position reports at each waypoint.
Example Sentence 2
Without radar, the flight received procedural separation based on its last reported position and estimated time over the next waypoint.