All airspace is classified into two broad categories—controlled and uncontrolled. Controlled airspace has defined dimensions within which air traffic control service is provided to IFR (instrument flight rules) and VFR (visual flight rules) flights in accordance with airspace classification. The ICAO (International Civil Aviation Organization) has created seven classifications of airspace, with A to F as controlled airspace and class G as uncontrolled airspace. In the United States, there are six classes of airspace, with A to E as controlled airspace and G remaining uncontrolled airspace. There is no airspace class F in the U.S. airspace structure. The airspace classifications as laid down by the ICAO (International Civil Aviation Organization), the FAA (Federal Aviation Administration), and the CAA (Civil Aviation Authority) are shown in the illustrations (see pages 53–54). The illustration also gives the broad parameters for operations in these airspaces as laid down by the ICAO and the FAA.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved