Controlled classes
Class A is IFR only with full separation. B, C and D admit VFR with clearance and progressively lighter services. Class E is controlled for IFR but VFR needs no clearance.
Uncontrolled classes
Class F offers an advisory service and G none at all beyond information. Separation there is the pilot's responsibility.
Special areas
Prohibited, restricted and danger areas plus temporary reserved airspace overlay the classes. NOTAMs activate them, so a briefing is worthless if it is not current.
Key points
- Class A: IFR only. Class G: no clearance, no separation.
- The class determines the service you receive, not just the paperwork.
- Airspace status changes daily — always check NOTAMs.
Knowledge check