Hello,

I was wondering is there a way to fly RNAV routes and/or approaches in FSX?

Thanks,

RNAV and GPS approaches are usually the same. In fact, most (if not all) RNAV approaches in the US actually show "RNAV (GPS)" in the title of the chart. If you are using the default navigation in FS, you can use a GPS approach instead of the corresponding RNAV approach, and you won't notice any difference in most cases. The key thing to remember though, is that RNAV and GPS approaches do not provide any vertical guidance other than minimum crossing altitudes. You have to handle the actual descent portion of the approach yourself.

Moved to training.