Setron,
Totally off topic with reference to the thread. Live no where near the desert....went no where near the ERJ135 which I think you are referring to and still reside in GP working for the fellas across the Charlie apron.
Anyway I seem to remember high speed descents into Cape Town by a certain training captain or other but fella it ain't me so somewhere along the line you must have your wires crossed.
So be it and believe what you want. I drove J41's.........and 240kts was the order of the day. But my memory fades as it was a long time ago!