In the US there are ' GPS Overlay' approaches which are basically a NPA such as VOR but overlayed on top is the GPS prcedure...which is exactly the same...
So if I was shooting a NPA in the UK and I had an IFR GPS fitted I would set up the approach in the GPS, and use this alongside my conventional nav equipment. If I had a problem with the conventional equipment, I'd follow the GPS....
Cheers
EA
