CNN article on problems in Air Travel, as seen by FAA

John Kulp wrote:

What makes you think that GPS could decrease the needed separation?


Because that is exactly what it is designed to do?

Ah, no. GPS was not designed for that nor can it provide that. Most in
trail separation today is based on wake turbulence. Even if you got rid
of wake turbulence you still can't get less than 2.5-3 miles for jets
because that's how long it takes to land, slow down and exit the runway.
If it's dry. And that spacing doesn't allow departures to get out
between the arrivals. So you go to five miles and if everything works
out perfect that's barely enough room to get the jet departures out.
The plain simple fact of the matter is the limiting factor is lack of
runways. No amount of technology can force more airplanes onto the
runways we have now.

Recently, Newps posted:

[...] The plain simple fact of the matter is the limiting
factor is lack of runways. No amount of technology can force more
airplanes onto the runways we have now.

Isn't that somewhat dependent on the definition of "...the runways we have
now"? The problem is easily addressed by abandoning the hub system that
overburdens a few locations and barely worked when demand was low.
Alternatively, add hubs to some of the underutlilzed airports. Of course,
the airlines would probably find this to be a threat to direct service to
locations of highest demand, but from a passenger's point of view, it's
becoming more difficult to get a flight direct to very many places anyway.

Neil

Neil Gould wrote:
Recently, Newps posted:

[...] The plain simple fact of the matter is the limiting
factor is lack of runways. No amount of technology can force more
airplanes onto the runways we have now.

Isn't that somewhat dependent on the definition of "...the runways we
have now"? The problem is easily addressed by abandoning the hub
system that overburdens a few locations and barely worked when demand
was low. Alternatively, add hubs to some of the underutlilzed
airports. Of course, the airlines would probably find this to be a
threat to direct service to locations of highest demand, but from a
passenger's point of view, it's becoming more difficult to get a
flight direct to very many places anyway.

Neil

Sure that will work but to do it would mean more smaller aircraft in the
system, which I don't personally think is a bad thing but it could bring
about another problem where the ATC is over burdened. Of course it is a lot
easier to hire and train mor controllers than it is to build more runways.

Recently, Gig 601XL Builder wrDOTgiaconaATsuddenlink.net posted:

Neil Gould wrote:
Recently, Newps posted:

[...] The plain simple fact of the matter is the limiting
factor is lack of runways. No amount of technology can force more
airplanes onto the runways we have now.

Isn't that somewhat dependent on the definition of "...the runways we
have now"? The problem is easily addressed by abandoning the hub
system that overburdens a few locations and barely worked when demand
was low. Alternatively, add hubs to some of the underutlilzed
airports. [...]


Sure that will work but to do it would mean more smaller aircraft in
the system, which I don't personally think is a bad thing but it
could bring about another problem where the ATC is over burdened. Of
course it is a lot easier to hire and train mor controllers than it
is to build more runways.

It's especially pointless to build more runways in the same overtaxed
hubs. Furthermore, it might not matter if there are more aircraft in the
air as long as they aren't all going to the same place. From what I
gather, the overload is derived from the number of arrivals & departures
at peak times. Spread that out, and the load drops. The more ways that
gets spread out, the better the system should function.

Neil

On Wed, 31 Oct 2007 09:04:04 -0600, Newps wrote:



John Kulp wrote:

What makes you think that GPS could decrease the needed separation?


Because that is exactly what it is designed to do?

Ah, no. GPS was not designed for that nor can it provide that. Most in
trail separation today is based on wake turbulence. Even if you got rid
of wake turbulence you still can't get less than 2.5-3 miles for jets
because that's how long it takes to land, slow down and exit the runway.
If it's dry. And that spacing doesn't allow departures to get out
between the arrivals. So you go to five miles and if everything works
out perfect that's barely enough room to get the jet departures out.
The plain simple fact of the matter is the limiting factor is lack of
runways. No amount of technology can force more airplanes onto the
runways we have now.

Funny none of the airlines I know of are saying this. They are all
advocating just this upgrade and the FAA is going to have it build.
So just what do you know that those running the business don't?

John Kulp wrote:

Ah, no. GPS was not designed for that nor can it provide that. Most in
trail separation today is based on wake turbulence. Even if you got rid
of wake turbulence you still can't get less than 2.5-3 miles for jets
because that's how long it takes to land, slow down and exit the runway.
If it's dry. And that spacing doesn't allow departures to get out
between the arrivals. So you go to five miles and if everything works
out perfect that's barely enough room to get the jet departures out.
The plain simple fact of the matter is the limiting factor is lack of
runways. No amount of technology can force more airplanes onto the
runways we have now.


Funny none of the airlines I know of are saying this. They are all
advocating just this upgrade and the FAA is going to have it build.
So just what do you know that those running the business don't?

GPS was designed and built by the military. Imagine that, the airlines
not wanting to change anything but have others change to meet their
outmoded business plan. You can't change basic physics. GPS can
generate some minor efficiencies in getting aircraft to the start of the
arrival which is 150 nm from the airport. Then everybody gets lined up
and fed to the airport. GPS is of little value from that point on in
reducing spacing. How are you going to overcome the basic fact that
2.5-3 miles is the minimum useable spacing, assuming no departures?
Many studies have been done that the optimal runway occupancy time is
approx 45 seconds for a landing aircraft. More typical is 1 minute, in
good weather. That's approx 2.5-3 miles separation. You want more
operations? Lay more concrete.

On Wed, 31 Oct 2007 11:34:47 -0600, Newps wrote:



John Kulp wrote:

Ah, no. GPS was not designed for that nor can it provide that. Most in
trail separation today is based on wake turbulence. Even if you got rid
of wake turbulence you still can't get less than 2.5-3 miles for jets
because that's how long it takes to land, slow down and exit the runway.
If it's dry. And that spacing doesn't allow departures to get out
between the arrivals. So you go to five miles and if everything works
out perfect that's barely enough room to get the jet departures out.
The plain simple fact of the matter is the limiting factor is lack of
runways. No amount of technology can force more airplanes onto the
runways we have now.


Funny none of the airlines I know of are saying this. They are all
advocating just this upgrade and the FAA is going to have it build.
So just what do you know that those running the business don't?

GPS was designed and built by the military.

So what? I use it all the time in my car to find where I am and where
I'm going. Just like the airlines want.

Imagine that, the airlines
not wanting to change anything but have others change to meet their
outmoded business plan.

Imagine you not knowing what you're talking about. The airlines have
made huge changes in their business plans which you obviously know
nothing about.

You can't change basic physics. GPS can
generate some minor efficiencies in getting aircraft to the start of the
arrival which is 150 nm from the airport. Then everybody gets lined up
and fed to the airport. GPS is of little value from that point on in
reducing spacing. How are you going to overcome the basic fact that
2.5-3 miles is the minimum useable spacing, assuming no departures?

Uh, when someone else pointed out that it is currently 5-6miles you
don't call that increased efficiency? Where did you study math?

Many studies have been done that the optimal runway occupancy time is
approx 45 seconds for a landing aircraft. More typical is 1 minute, in
good weather. That's approx 2.5-3 miles separation. You want more
operations? Lay more concrete.

a. what studies?

b. that would increase efficiency about 50% if it is currently 6 miles
wouldn't it?

John Kulp wrote:
On Wed, 31 Oct 2007 11:34:47 -0600, Newps wrote:




John, you seem to be under the impression that GPS is going to somehow
manage to change the physics of time and space. Yes, when airlines use GPS
they can fly direct from point A to point B but if A and B are crowded they
are still going to have to wait on the ground to take off and fly around in
circles waiting to land.

On Wed, 31 Oct 2007 14:07:55 -0500, "Gig 601XL Builder"
wrDOTgiaconaATsuddenlink.net wrote:

John Kulp wrote:
On Wed, 31 Oct 2007 11:34:47 -0600, Newps wrote:




John, you seem to be under the impression that GPS is going to somehow
manage to change the physics of time and space. Yes, when airlines use GPS
they can fly direct from point A to point B but if A and B are crowded they
are still going to have to wait on the ground to take off and fly around in
circles waiting to land.

Where did I say this? I said that if spacing can be reduced due to
safer wake turbulence management then GPS can be used to safely close
those spaces and improve the capacity of the system. That's all.
Just where do you think I am confused. And, if I am wrong (or
confused)

a. why is the FAA going ahead with the building of the system?

b. why are the airlines backing that change?

On Wed, 31 Oct 2007 19:52:22 GMT, (John Kulp)
wrote in :


a. why is the FAA going ahead with the building of the system?

The former Clinton administration opposed ATC privatization.

The current administration wants to privatize virtually every
government service. In the case of the FAA, privatization would
enable FAA to cut their workforce significantly, dodge liability
exposure, and open the federal coffers to by outsourcing to big
business.

Big business benefits from government privatization. Consider
Halliburton's contract to do the Army's laundry in Iraq[1] for
example.

Privatization also removes government accountability; private
corporations are not subject to FOIA requests, for example.


b. why are the airlines backing that change?

The airline industry, including the airliner manufacturers, would like
nothing better than to remove congressional FAA budget oversight, and
wrest the balanced governmental allocation of National Airspace System
resources from US citizens, so that they can advance their air carrier
agenda at the expense of other airspace users. Airliner manufacturer,
Boeing, is also in the privatized ATC business.[2]





[1]
http://video.google.com/videoplay?do...=iraq+for+sale
http://www.youtube.com/watch?v=6cJlJudDtVE
http://www.iraqforsale.org



[2] http://www.boeing.com/phantom/ast/atm.html