"Me" wrote in message
...
In article G_4yd.8097$iD.5755@fed1read05,
"Jim Donohue" wrote:

"Jeff Morris" wrote in message
...

Are you sure of that? Are you really claiming that the thousands of
jets
that are in the air now completely rely on GPS and would be unable to
land
without it? Are you actually telling me that when I board a 757 to go
to
FL for Christmas the only nav system on board will be a GPS?

I am not sure what point you are making. There are airport approaches
that
can only be executed by a GPS equipped airplane. So under at least some
weather conditions the only way to get into that airport is to fly a GPS
approach.

There are airplanes under the existing regulations that lack equipment
that
used to be required for some instrument approaches.

All airplanes can of course resort to visual approaches. So when
everything
breaks, you can run for a place where you can see. Note though that
occassionally there are no such places available.

I am not aware of any precision approach that has been approved for GPS.
Maybe Me knows something I don't. If so I would like to see a reference.

There appears no doubt in the direction of the FAA that the system will
go
entirely GPS eventually...but that point is still many years in the
future.
The present state is one of transition...changing from the procedures of
VOR/DME to those of GPS. So every year more and more of the procedures
will
be GPS.


JIm Donohue



Juneau, Alaska check it out....... the ILS Approch has a 45 degree
DogLeg 1000 feet before the end of the runway. Try that with the
old Ground based ILS system........


Me

Only published approach is RNAV non-precision approach. No dog leg close
in. There was a very sophisticated early experiment at Juneau that may have
been what your are referring to.

A quick check of the literature indicates there are no CAT I or better GPS
approaches. LAAS is supposed to enable this and there is talk that a
combination with Galileo will eventually enable precision approaches. I
believe at one point they were projecting CAT I with WAAS but decided
integrity is not high enough.

Jim