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

John Kulp wrote:


Gates can be a problem sometime but not runways. The GPS system would
handle about 25% more flights on the same runways. Aren't you paying
enough all ready for flights? Want to pay more when the politicos are
stealing what money is already being paid for?

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

I didn't say anything about paying more. What I suggested in this forum a
month or so ago was the same net cost just make it cheaper off peak and more
expensive on-peak. That's how economics should work. Things should cost more
when they are in higher demand and less when they are in lower demand.

On Tue, 30 Oct 2007 08:26:51 -0500, "Gig 601XL Builder"
wrDOTgiaconaATsuddenlink.net wrote:

John Kulp wrote:


Gates can be a problem sometime but not runways. The GPS system would
handle about 25% more flights on the same runways. Aren't you paying
enough all ready for flights? Want to pay more when the politicos are
stealing what money is already being paid for?

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

Because that is exactly what it is designed to do?


I didn't say anything about paying more. What I suggested in this forum a
month or so ago was the same net cost just make it cheaper off peak and more
expensive on-peak. That's how economics should work. Things should cost more
when they are in higher demand and less when they are in lower demand.



Well, I didn't see your post then so I can't comment

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

Because that is exactly what it is designed to do?

It _may_ be able to more precisely control separation out in the airways,
and get them set up for landing sequence, but notice I said "may." They do
a pretty good job with radar, right now.

What it _can not_ do is put more aircraft on the runways per hour in the big
airports operating with all of the landing slots full. The separation for
wake turbulence is always going to be the limiting factor in how many
aircraft can land at a given busy airport at peak times. GPS is not going
to change that.
--
Jim in NC

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?