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

"John Kulp" wrote

GPS allows for closer spacing and straighter flight paths allowing
more flights to be handled in the same time span. About 25% more.

If they are heavies, the separation for wake turbulence is what the limiting
factor for separation, isn't it?
--
Jim in NC

On Mon, 29 Oct 2007 22:27:34 -0400, "Morgans"
wrote:


"John Kulp" wrote

GPS allows for closer spacing and straighter flight paths allowing
more flights to be handled in the same time span. About 25% more.

If they are heavies, the separation for wake turbulence is what the limiting
factor for separation, isn't it?

Well, wake turbulence is certainly a factor, particularly for the A380
which may slow down things even further. Which raises the question as
to whether it should be penalized more than others if they start to
use penalties.

Morgans wrote:

"John Kulp" wrote

GPS allows for closer spacing and straighter flight paths allowing
more flights to be handled in the same time span. About 25% more.


If they are heavies, the separation for wake turbulence is what the limiting
factor for separation, isn't it?

You need up to six miles behind a heavy. Your spamcan needs four miles
behind a large, such as a B737. To say GPS increases available capacity
25% is ludicrous.

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

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?