Definition
Class G airspace is uncontrolled airspace — the portion of the atmosphere where air traffic control does not provide separation services to any aircraft. It exists from the surface up to the base of the overlying controlled airspace (typically Class E), and pilots operating in it are responsible for their own traffic separation and terrain avoidance. VFR weather minimums are lower than in controlled airspace, and no clearance, communication, or transponder requirements apply for entry.
Plain English
Class G is the airspace that ATC does not control. Pilots flying in it look out for other aircraft themselves and don't need permission or radio contact to be there.
Context Anchor
Seen in airspace diagrams, sectional charts, weather minimum discussions, and instrument training when comparing controlled and uncontrolled airspace.
Derivation
“Class” comes from the idea of a category or group. In aviation, the letters A through G are labels for different categories of airspace; “G” is not an abbreviation and does not stand for a word.
Why Pilots Care
Pilots must maintain their own separation from other traffic and obstacles, and they can operate without contacting ATC in most situations.
Intuition Check
Do not read “Class G” as a grade or quality level. It is simply one named category of airspace, and its key feature is that it is uncontrolled.
Example Sentence 1
Departing the small grass strip, the pilot climbed through Class G airspace before entering the overlying Class E at 1,200 feet AGL.
Example Sentence 2
In Class G airspace below 1200 feet AGL, the pilot maintained visual separation from terrain and other aircraft.