English as she is spoke....
I think the rub here is that if everybody in the same airspace speaks and understands the same language, safety goes up a lot. How many of you have been inbound in IMC in the DRC with aircraft wizzing around and everybody speaking French?
Very bloody confusing if not scary. I like to build a mental picture of where everybody is in relation to me when I am in the hold or on the approach to a field, especially on the dark continent!
Seems to me a grasp of the language should be essential?