Plain English Meaning

A catch-all label the FAA uses for airspace that doesn't fit neatly into the lettered classes. These are special-purpose areas pilots still need to know about and account for when planning a flight.

Full Definition

A category used by the FAA to group several types of airspace that fall outside the standard controlled (Classes A, B, C, D, E) and uncontrolled (Class G) classifications. It includes areas such as local airport advisory areas, military training routes, temporary flight restrictions, parachute jump areas, published VFR routes, terminal radar service areas, and national security areas.