Earlier in this discussion, the question of SA CAA approval to carry out RNP approaches came up. One participant said that ZA crews could not utilize such approaches without the express permission of the SA CAA. That struck me as being a bit odd, because in other countries (Europe, Canada) crew can fly published RNP approaches as long as the aircraft has the appropriate equipment installed and the crew are appropriately qualified (instrument rating) to fly the approach.
I did find a document published by the SA CAA that provides some clarification, that document is here:
OPERATOR AIRCREW AND AIRCRAFT APPROVAL FOR REQUIRED NAVIGATION PERFORMANCE CA AOC-AC-FO-012.
As is so often the case in aviation worldwide, a distinction is made between 'operators' and 'pilots'. In this case, the document applies to SA 121 and 135 operators, not globally to all South African pilots. But, I don't think any of us yet know what operating certificate was applicable to this flight - was it AirServ's Part 91 American certificate, Cem Air's certificate (if they have one), Star Air Cargo's certificate, or no certificate at all?
A prerequisite for anyone - pilot or operator - to carry out RNP approaches is that the aircraft must be equipped with avionics that provide the required RNP precision for the approach. It's not sufficient that the avionics box itself meet the TSO specification, it also has to be installed in accordance with the TSO requirements, and the navigation database in it must be kept up to date.