If you plan on flying a helicopter you need to know something about what you’re going to be flying in. Canadian Airspace is divided into several categories and then subdivided into areas and zones.
In Southern Domestic Airspace we make reference to the magnetic compass for aircraft tracks, headings, runway directions and wind direction. Wind direction is only magnetic when it is said on the radio. If you see it written down the direction is referenced to true geographic North.
Magnetic compasses are not very reliable as you get closer to the magnetic North pole. For this reason in Northern Domestic Airspace all aircraft tracks, headings, runway numbers and wind are referenced to Geographical North.
Airspace is also divided into controlled, where some sort of Air Traffic Control Service is provided, and uncontrolled where there is not. There are 7 different classes of Airspace and the requirements to enter them vary. You can see them on the chart below.
As well as knowing the equipment required for each class of airspace you also need to know the weather requirements to be in that class. We will cover these in detail in the next Helicopter Ground School Blog post. You need to know these minimum by heart. Any competent helicopter pilot can look at a navigational chart, see what airspace they will be flying through and be able to rattle off the required weather minimum.
Airspace around controlled airports is called the Terminal Control Area (TCA). The class of airspace around a controlled aerodrome will depend on how busy it is. Busy airports will require higher levels of Air Traffic Services and may also mean stricter requirements for an aircraft to be able to enter that airspace.
The TCA is often referred to as the upside down wedding cake and you can see why in the diagram from Transport Canada above. The class of airspace will depend on how busy that airspace is expected to be and the services required.
The Control Zone
Control zones are there to keep aircraft flying under Instrument Flight Rules (IFR) in controlled airspace. They start on the ground and go up to 3000 Ft Above Aerodrome Elevation (AAE) with a radius of 7nm as standard but they can be different.
If the Control Zone is not the standard height it will be shown around the Obstacle Clearance Circle (OCC) in the Canadian Flight Supplement (CFS). See below.
Transition Zones and Control Area Extensions (CAE)
When an IFR aircraft makes a descent to an airport it’s possible for it to drop out of the wedding cake and into uncontrolled airspace. For this reason some airports will have a transition zone and maybe a CAE as well. Transition zones are always Class E airspace that starts at 700 ft Above Ground Level (AGL) and go up to the overlying airspace. They have a radius of 15 nm from the center of the control zone.
Control Area Extensions serve the same purpose as a transition zone. They start at 2200 FT AGL and extend up to 18,000 FT Above Sea Level (ASL). They will surround and overlie the core control zone. There is no standard radius, (they may not even be a circle) the shape and size will vary depending on the needs of the aerodrome.
Transition Area and Control Area Extension around Grande Prairie airport (CYQU).
Class A and B
A final note on Class A airspace and Class B. All airspace over Canada’s landmass, the arctic and certain parts of the high seas becomes Class A at 18,000 FT ASL.
All airspace within the controlled airspace boundary (this can be seen on your navigational chart) becomes Class B at 12,500 FT ASL.
And there you have it. A quick summary of Canadian Airspace. There is much more to talk about but we’ll save that for another day.