Airspace of defined dimensions identified by an area on the surface of the earth wherein activities must be confined because of their nature and/or wherein limitations may be imposed upon aircraft operations that are not a part of those activities:

1. Alert Area- Airspace which may contain a high volume of pilot training activities or an unusual type of aerial activity, neither of which is hazardous to aircraft.
2. Controlled Firing Area- Airspace wherein activities are conducted under conditions so controlled as to eliminate hazards to nonparticipating aircraft and to ensure the safety of persons and property on the ground.
3. Military Operations Area (MOA)- Permanent and temporary MOAs are airspace established outside of Class A airspace area to separate or segregate certain nonhazardous military activities from IFR traffic and to identify for VFR traffic where these activities are conducted.
4. National Security Area (NSA)- Airspace of defined vertical and lateral dimensions established at locations where there is a requirement for increased security of ground facilities.
5. Prohibited Area- Airspace designated under 14 CFR part 73 within which no person may operate an aircraft without the permission of the using agency.
6. Restricted Area- Permanent and temporary restricted areas are airspace designated under 14 CFR part 73, within which the flight of aircraft, while not wholly prohibited, is subject to restriction.
7. Warning Area- A warning area is airspace of defined dimensions extending from 3 nautical miles outward from the coast of the United States, that contains activity that may be hazardous to nonparticipating aircraft.

Listed in the Pilot/Controller Glossary as a cross-reference to SPECIAL USE AIRSPACE, whose text is shown above.

Source FAA Pilot/Controller Glossary↗ · checked 2026-08-25