Sam,

When you
select a LOC or ILS, you instead receive an advisory message cautioning
you that RNAV is for monitoring only.


Yes, but you can (and should, per the manual) activate them. So the
question remains, what exactly does that do? In my experience, it starts
both sequencing of the waypoints in the procedure and the change in CDI
sensitivity. And from my experience, same goes for an RNAV approach. The
430 just continues to fly the original flightplan if you don't make it fly
the approach - by activating it.



--
Thomas Borchert (EDDH)