Definition
The responsibility for keeping a VFR (Visual Flight Rules) aircraft safely apart from other aircraft. Depending on the airspace class, this responsibility either rests entirely with the pilot using see-and-avoid, or is shared with air traffic control, which may provide traffic advisories or actual separation services.
Plain English
Who is responsible for making sure a VFR aircraft does not get too close to other aircraft. In some airspace, the pilot handles it alone by looking out the window. In other airspace, ATC helps by calling out traffic or actively keeping aircraft apart.
Context Anchor
Seen in airspace classification tables and discussions of what services pilots receive in Class B, Class C, Class D, and other airspace.
Derivation
VFR means visual flight rules: flying mainly by looking outside and staying in weather good enough for that. Separation comes from a word meaning “to set apart,” which fits the aviation meaning: keeping aircraft far enough apart to reduce collision risk.
Why Pilots Care
Knowing when separation is provided helps VFR pilots maintain the right level of vigilance and avoid surprises in busy airspace.
Intuition Check
Do not assume “separation” means a controller is keeping you away from all traffic at all times. In this context, it means a specific spacing service that applies only in certain airspace and situations.
Example Sentence 1
In Class C airspace, VFR aircraft separation from IFR traffic is provided by ATC, but separation from other VFR aircraft is limited to traffic advisories.
Example Sentence 2
In Class E airspace, VFR aircraft separation is not provided by ATC.