Controlled airspace

Not to be confused witharea control center.

Controlled airspaceisairspaceof defined dimensions within whichair traffic control(ATC) services are provided.The level of control varies with differentclasses of airspace.Controlled airspace usually imposes higher weather minimums than are applicable in uncontrolled airspace.It is the opposite ofuncontrolled airspace.

Schematic representation of the main controlled airspace types and the air traffic control offices that respectively provide control service inside these airspaces. "TMA" is an abbreviation forTerminal Manoeuvring Area( "Terminal Control Area" outside Europe)

Controlled airspace is established mainly for three different reasons:

• high-volume air traffic areas, e.g. near airports
• Instrument flight rulestraffic under ATC guidance
• security, e.g. within anair defense identification zone

Controlled airspace usually exists in the immediate vicinity of busier airports, where aircraft used in commercial air transport flights are climbing out from or making an approach to the airport, or at higherlevelswhere air transport flights would tend to cruise. Some countries also provide controlled airspace almost generally, however in most countries it is common to provide uncontrolled airspace in areas where significant air transport or military activity is not expected.

TheInternational Civil Aviation Organizationdivides airspace into seven classes, fromA to G,in order of decreasing ATC regulation of flights. Classes A to E are controlled airspace. Flight underinstrument flight rules(IFR) is allowed in all controlled airspace. Some countries also permit IFR in uncontrolled airspace). Flight undervisual flight rules(VFR) is permitted in all airspace except class A.

See also

• Airspace class
• Prohibited airspace
• Restricted airspace
• Special use airspace
• Terminal control area