I think you will find many Airline fleets fully equipped with GPS today. It
appears that GPS is well on its way to become the standard primary
navigation system with VOR/DME as the secondary backup system.

For sophisticated operation it appears likely that GPS will be combined with
inertial.

The marine problem is in general much simpler. It is nice to be able to
stop or go real slow...a tactic not available in an airplane.

Jim

"Jeff Morris" wrote in message
...
My point was simply that although the FAA has started approval GPS in some
situations, commercial flights, in particular large jets flying into major
cities, do not rely on GPS.

AnchorLt implied that anyone flying at the time of a GPS outage could be
in for "an ending." I think that commercial flights would be able to cope
since they do not rely exclusively on GPS. "me" rather rudely pointed out
the the FAA has begun approving GPS in some situations, some I pointed out
a few days ago, but missed the point the GPS is not the sole means used by
commercial aircraft.

I appreciate that there may be some situations GPS is the only way to get
into some airports, and that there may be not other backup. But this
scenario would apply to very few, if any commercial aircraft today.

Curiously, the scenario I remember given when SA was removed in 2000 was
that the 300 foot uncertainty in location meant that rescue vehicles might
go to the wrong side of a divided highway, causing perhaps fatal delays.
I wonder if the administration has some breakdown of the cost in lives,
accidents, and economic loss if GPS were shut down?


Jim Donohue wrote:
"Jeff Morris" wrote in message
...