Airspace in which aircraft are not subject to controlled airspace (Class A, B, C, D, or E) separation criteria.
Source FAA Pilot/Controller Glossary · checked 2026-08-25
Airspace in which aircraft are not subject to controlled airspace (Class A, B, C, D, or E) separation criteria.
Source FAA Pilot/Controller Glossary · checked 2026-08-25