Definition
The separation of all air traffic within designated airspace by air traffic control, where each aircraft's position, altitude, and heading are actively known, monitored, and directed.
Plain English
In certain airspace, ATC is actively keeping every aircraft apart by tracking them and giving instructions, rather than leaving it to pilots to see and avoid each other.
Context Anchor
Seen in air traffic control and airspace discussions, especially when describing areas where controller-provided separation applies to all aircraft.
Derivation
From Latin 'positivus,' meaning 'settled' or 'firmly established.' Here 'positive' means definite and active — control is actually being exercised, not assumed. It contrasts with airspace where separation depends on pilots looking out the window.
Why Pilots Care
Tells the pilot whether ATC or the pilot is primarily responsible for collision avoidance and route compliance.
Intuition Check
Positive does not mean good or approved here. Control does not mean the controller is flying the airplane. Positive control means air traffic control is actively providing separation between aircraft in that airspace.
Example Sentence 1
Above 18,000 feet MSL, all aircraft operate under positive control by ATC.
Example Sentence 2
The controller confirmed positive control was active before issuing the altitude change.