Canadian airspace

[2] The "Canadian Domestic Airspace" includes all of Canada and extends out over the Pacific, Arctic, and Atlantic oceans.

This means that pilots operating in the SDA will calibrate their altimeters to atmospheric pressure according to information available at airports and through weather services.

Conversely, in the NDA, pilots calibrate their altimeters to 29.92 inches of mercury (101.3 kPa) regardless of the actual atmospheric pressure.

So uncontrolled airports like Sarnia (CYZR) and others may appear to be mischaracterized as control zones since the Canadian Air Regulations (CARs) define a CZ as "controlled airspace that is so specified in the Designated Airspace Handbook (DAH)[8] and that extends upwards vertically from the surface of the earth up to and including 3,000 feet AGL, unless otherwise specified" in that handbook.

DAH also defines "Class B, C, D or E equivalent" airspace but that specifically refers MTCAs which are military terminal control areas.

Another important feature of Canadian airspace is the air defence identification zone (ADIZ) that surrounds North America.

The terminal control areas of the French islands of Saint Pierre and Miquelon are located within Canadian airspace.