There are some things that non-airline pilots shouldn't be making definitive statements about. Google RNP.
Firstly, I didn't make a definitive statement, I expressed an opinion. You can tell because it started with " I think.." In this instance I may be wrong. Although, my reading so far indicates that RNP is a navigation tolerance standard which is technology agnostic - it can be achieved with VOR, INS, DME and possibly other systems. I understand RNP originated in Europe and uses angular clearance tolerances rather then height or vice versa. Either way it requires full procedure redesign.
Secondly, I think the Queenstown GPSS RNAV RNP approach (which is the poster girl for RNP approaches) has been around for maybe 10 years? Or more? I think it was originally developed using an Apollo CNS-80. It doesn't really seem to be catching on. Which is my point, that (especially with airline capital expenditure programmes) these things are long linked.
As I understand it, a precision RNP approach requires an additional altitude input. This can be from either WAAS (back to the WAAS debate) or a precision barometric input, which I assume has to be part of the Flight Management System. This barometric input can also turn a VOR NPA into a VOR RNP precision approach.
If I read the draft CASA CAAP correctly (AC-91U-II-C-5), it says that Australia will only develop RNP VNAV approaches (ie precision approaches) if we "acquire a GNSS augmentation system". In other words, we'll only get precision RNP approaches if we install WAAS beacons, which I understand is not on the agenda.
Which brings us full circle back to ILS.
How did I do for a non-airline guy?