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

In article ,
(Baybyter) wrote:

In a message dated 12/20/2004 1:43:11 PM Eastern Standard Time,
writes:
How many boats have you been on in the past five or so years that have
on their nav table: a divider, a chart ruler, or anything like these
simple and other nav instruments? I would guess you have found very
few, indeed if any.

Ahoy:

I have to admit that (1) my boat does have a nav table, dividers, and other
simple chart plotting tools, and that (2) I hardly ever use them.... I'm not
sure what other boater friends of mine have, but you've peaked my curiousity
to
find out. Having said all this, I also agree that most of us do, in fact,
depend on the GPS alone more often than not. But if you are like me, I also
have something of an "eyeball DR" going on in my head almost all of the time.
This served me well once when I was navigating a course on the GPS to a
distant
marker. At some point, the "eyeball DR" in my brain kicked in to say that
what
I was seeing did not look right. I was way off course. It turned out that I
had transposed the waypoints for my destination when I loaded them into my
GPS....It was an interesting lesson that happily ended well

Good sailing to you.

w.


Obviously, You have NEVER been on a Commercial Vessel bigger than 100
tonsGW. Every one I have been on has those, and a lot more. You
Weekend Masters ought to look at how the BIG BOYS navigate, and then
come back and tell us all what you found.......

Me

On 21 Dec 2004 15:15:35 GMT, (Baybyter) wrote:

In a message dated 12/20/2004 1:43:11 PM Eastern Standard Time,
writes:
How many boats have you been on in the past five or so years that have
on their nav table: a divider, a chart ruler, or anything like these
simple and other nav instruments? I would guess you have found very
few, indeed if any.

Ahoy:

I have to admit that (1) my boat does have a nav table, dividers, and other
simple chart plotting tools, and that (2) I hardly ever use them.... I'm not
sure what other boater friends of mine have, but you've peaked my curiousity to
find out. Having said all this, I also agree that most of us do, in fact,
depend on the GPS alone more often than not. But if you are like me, I also
have something of an "eyeball DR" going on in my head almost all of the time.
This served me well once when I was navigating a course on the GPS to a distant
marker. At some point, the "eyeball DR" in my brain kicked in to say that what
I was seeing did not look right. I was way off course. It turned out that I
had transposed the waypoints for my destination when I loaded them into my
GPS....It was an interesting lesson that happily ended well

I also have a nav table that can take a chart folded in half. When we
are offshore, as when crossing the Gulf of Maine, we plot the GPS
and/or Loran (not DR) position hourly.

Any anomalous behaviour will show up long before it matters under
those circumstances.

But, inshore near rocky coasts, like a lot of Maine, we plot danger
bearings whenever we are tacking to windward. It is a great
convenience to know the bearing angle you can safely reach on the next
headland, without having to see exactly where you are along the
course.

On smoother or sandier shores, with spaced-out contour lines, we can
tack by the depth sounder.

The common thread in all of these is awareness of surroundings, and
how they matter for pilotage.



Rodney Myrvaagnes J36 Gjo/a

The destruction of the World Trade Center was
a faith-based initiative. -- George Carlin

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?

Baybyter wrote:
In a message dated 12/20/2004 1:43:11 PM Eastern Standard Time,
writes:
How many boats have you been on in the past five or so years that have
on their nav table: a divider, a chart ruler, or anything like these
simple and other nav instruments? I would guess you have found very
few, indeed if any.

Ahoy:

I have to admit that (1) my boat does have a nav table, dividers, and other
simple chart plotting tools, and that (2) I hardly ever use them.... I'm not
sure what other boater friends of mine have, but you've peaked my curiousity to
find out. Having said all this, I also agree that most of us do, in fact,
depend on the GPS alone more often than not. But if you are like me, I also
have something of an "eyeball DR" going on in my head almost all of the time.
This served me well once when I was navigating a course on the GPS to a distant
marker. At some point, the "eyeball DR" in my brain kicked in to say that what
I was seeing did not look right. I was way off course. It turned out that I
had transposed the waypoints for my destination when I loaded them into my
GPS....It was an interesting lesson that happily ended well

Good sailing to you.

w.

I'm not sure where anchorlt made the above comments - they don't show on
my servers or google. But ...

I'm a bit surprised at the comments - Certainly most of the long time
boaters I know have these tools and know how to use them. I'll admit
that most of them have given in to the temptation of relying on GPS, but
I'm sure all of them could cope with a sudden outage. For my own part,
I've lost GPS several times and found that I could revert to traditional
rather quickly if the need arises. As you say, a mental DR is always
maintained.

Although my boat is set up for computerized nav, I usually don't keep a
computer onboard. My GPS is 8 years old, and I haven't bothered getting
the charting chips for most areas I cruise to. Every year I do at least
one trip without GPS, just to stay in practice.

As for tools, I keep a set in a plastic box that comes on deck for
longer trips, or iffy weather. Although I don't often do running fixes
on deck, I usually do a few set and drift calculations a year. Frankly,
there's not much else to do when you're on a 4 hour watch; you might as
well practice navigation. (My wife, OTOH, saves a stack of magazines to
read while she's on watch, and thinks I'm just being geeky ...)

"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

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
...


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

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

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

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?