GPS and old-fashioned thinking?

In article ,
says...

I think the only problem with GPS is the human interface.

I disagree. I think there is a more important problem. If you're flying direct
routes and RNAV with GPS as primary(and only random route) source of
navigation, in the event of a GPS signal degradation, you have a bit of a
balancing act to do to get back to "legacy" navigation. If you're in the
middle of the Great Plains that's no issue, but if you're shooting an approach
to White Plains it may be.

My point is we were on the way toward an integrated RNAV system until GPS came
along and we decided we have to hurry and trash everything else. What we need,
I believe, is an RNAV system which allows us to seamlessly maintain random
route navigation in the event of a primary source failure (GPS). eLoran would
be one possible answer, but so would existing ground-based (VOR-DME) systems,
if your box is programmed for this.

The "all-or-nothing" approach to GPS (I know this is an exaggeration - but
only a slight one) is contrary to everything we learn and practice in aviation
- where we're supposed to have an answer, and hopefully a good answer, to
every eventuality.

I love GPS, and I see no problem in being highly reliant on it, because it is
intrinsically reliable - however I believe it would be practical and desirable
to build a system that maintains full RNAV capability in the event of a loss
in GPS integrity.

G Faris