I think Ascension was approved as a destination and an alternate. The plan was to continue the weekly flight to Ascension once a month. I'm not up on that region's alternate rules but the fuel for remote island dispatch or Ascension as an alternate is probably almost the same and the 738 and AXX's have that ability from S. Africa. The B-757 is a better aircraft all-around but has a slightly higher operating cost and nobody in Africa operates them. There are several UK 757 operators. The BAE 146 is the only near STOL but is marginal in range and payload. Apparently there are two flights a week from Brize Norton RAF to Ascension and Falklands. They should try to get a UK 757 operator to operate a passenger service once a week through Ascension, St. Helena and Capetown and keep the chartered A-330 for freight to Ascension and Falklands once a week. I think the 757 could handle the short runway and turbulence at St. Helena better. A payload would be assured on the long haul between Ascension and the UK and service to and from St. Helena and Capetown and the UK would be better.