Commercial airlines operate out of the following namibian airports:
-> Walvis Bay
Often the climb performance of these aircraft is not sufficient to reach FL 200 by the TMA boundary.
Therefor the TMZ zones are indroduced.
Here you can see the IFR airways and intersections.
Departing or arriving aircraft will usually fly along these IFR routes.
So when flying in the TMZ, please pay special attention, when crossing those routes.