Me wrote:
In article ,
Jeff Morris wrote:


Me wrote:

In article ,
Jeff Morris wrote:



Commercial flights do not rely on GPS for approaches.


Bzzzt, Wrong, Would you like to try for whats behind Door No. 1?

The FAA has certified CAT V GPS/ILS for about three years now.
It is a Aircraft Based System that only requires only a local
DGPS Beacon at the airport.


Me

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?


Yes, I am sure of that, as I service the system on a bunch of 737-400's.
This is an option for all Boeing jets now. I am not saying that ALL
Jets have this system, I am saying that there is a CAT V GPS/ILS that
is FAA Certified and in use in the USA. Most of the commercial
carriers are using Inertial guidance systems, and the GPS/ILS is an
additional option for the Approch and Landing phase of flight, that
CAN either replace the old Microwave Ground Based System or be a
Redundent System to it. I also would say that 90% of the commercial
Air Fleet, has GPS inputs to the Navigation systems onboard.
Hell I saw a superb Glass Cockpit installed in a Cessna Archer,
that used GPS as a PRIMARY Navigation Instrument, with VOR as the
redundant backup. This was installed by an FAA Grant on an alaskan bush
plane. $50K of your tax dollars for each installation and there are a
buch of them in service now.


Me

Even so, this doesn't mean that commercial flights *rely* on GPS; it
only means that they *use* GPS. There's a big difference.

So what do you think would happen if the feds decided they had to shut
down the GPS system?