It's a bit worrying when you think that they are talking about introducing RVSM in Africa. It's a shame that all that money paid in overflight charges doesn't reflect itself in more noticeable improvement in ATC across the continent; there are small advances such as Khartoum's increased VHF coverage but the huge voids as experienced by ETOPS are all too common. Does anyone know why we have several different control centres fighting for space on a handful of HF frequencies when individual airlines seem to be able to pick up a handful for their own use?