Originally Posted by Tom
This discussion is a good example why for modern air transport we ought to be flying RNP based procedures all the time, every time, IMC, VMC, day , night always
On particularly the first chart posted by OK465, I very much doubt that an RNP-AR approach could be designed over that ground track for "every time, IMC". It looks like it is essentially a visual downwind and close left base; wouldn't that be far too close for a "proper" RNP approach, Aterpster? I would wager that this was designed to fit in with tight airspace; the alternative, a "proper" RNP approach, would cost more and probably complicate the surrounding airspace.
We do hundreds of "RNAV Visuals". They work well. If a crew can't follow a set of waypoints (particularly if they come from a database procedure), with an auto-generated VNAV path to the threshold or at least the base turn point, then perhaps training should be improved...
I will say that here, our "RNAV Visual" approaches aren't flown by international crews. They do a full instrument procedure.