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/RMZ 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/RMZ zone, please pay special attention, when crossing those routes.