Control Zone

A control zone (CTR) is controlled airspace extending from the surface to a specified upper limit, surrounding an aerodrome that has a control tower. It provides protected airspace from the ground up within which all aircraft (IFR and VFR) are subject to ATC procedures.

Entering a Control Zone

Before entering a control zone, a VFR pilot must: obtain an ATC clearance (at Class C CTR) or establish two-way radio contact (at Class D CTR), have the weather minima that are appropriate for the airspace class, and comply with any ATC instructions. Entering a CTR without proper communication is a serious airspace violation.

Control Zone Dimensions

In Canada, CTRs are typically circular with a radius of 5 NM around the aerodrome reference point, extending to the base of the overlying terminal control area (typically 3,000 ft AGL). Dimensions vary and are published on VFR charts and in the CFS.

On the TC Written Exam

Know that the CTR is Class C or D at most Canadian airports; know the entry requirements for each class; and know that Class C requires ATC clearance while Class D requires two-way radio contact only.

Related Terms

See also: Control Tower, Controlled Airspace, Classification of Airspace.