Uncontrolled airspace

In aviation, uncontrolled airspace is airspace in which an Air Traffic Control (ATC) service is not deemed necessary or cannot be provided for practical reasons. It is the opposite of controlled airspace. It is that portion of the airspace that has not been designated as Control Area, Control Zone, Terminal Control Area or Transition Area.

According to the airspace classes set by the International Civil Aviation Organization (ICAO), the uncontrolled classes of airspace are class F and G.