Oliver Keating wrote:
"Aidan Stanger" wrote...
Angus Bryant wrote:

This seems deeply concerning. If air traffic growth continues at it's
present rate, then in 50 years time air travel will account for 40% of
all CO2 (greenhouse gas) emmissions.

And it's put directly into the upper atmosphere which has more of a
detrimental effect than if it were released at ground level.

I've heard this claim an awful lot, but not an explanation as to why.
What effect does CO2 have in the upper atmosphere that it does not have
at ground level?

The green house effect is caused by CO2 in the upper atmosphere bouncing
back infra-red radiation to the earth.

Are you sure? I thoght it was caused by the atmosphere absorbing the
radiation.

The fact is, incoming radiation from the sun is high frequency because the
sun is very hot. CO2 is transparant to high frequency radiation.

Incoming radiation is a mixture of high and low frequencies.

The Earth is much cooler, so it emits low-frequency radiation, which CO2
absorbs and reflects - hence greenhouse.

I'd not heard anything about the reflection effects of CO2 before. Have
you got a source for that?

However, I had heard about the reflection effects of H2O, of which there
is quite a lot in aircraft exhaust emissions. The URL Angus supplied
confirms that H2O in the stratosphere is thought to be a problem due to
the amount of back radiation it reflects being slightly higher than the
amount of incoming radiation it reflects - although scientists are far
from certain on this.

CO2 at ground level has little effect, but in the upper atmosphere its where
it really has it's effects. So in theory, a pollution source that puts CO2
straight up there, rather than at ground level will do more harm.

You say it's the upper atmosphere where CO2 really has its effects.
Other than reflecting some of the radiation back down towards the
ground, what harmful effect would it have?

The argument is slightly spurious because atmospheric gases have an
excellent mixing coefficient, and any local high concerntrations of CO2 will
be rapidly mixed until the concerntration is nearly uniform - indeed recent
analysis found that the concerntration of CO2 was extremely constant around
the world.

On Wed, 17 Dec 2003 15:13:16 +0000, Lansbury wrote:

On Wed, 17 Dec 2003 08:01:22 +0000, Steve Peake
wrote:

How could I have guessed that a 3rd runway was on the
cards, especially when the 5th terminal inspector placed a flight cap on
the airport?

perhaps because the plans for the third runway were drawn up years ago.
It didn't take a rocket scientist to anticipate that one day there was a
chance they might come to something.

I'll repeat myself, why would a 3rd runway be needed while there was a
flight cap in place?

Steve

On Thu, 18 Dec 2003 07:17:50 +0000, Steve Peake
wrote:

I'll repeat myself, why would a 3rd runway be needed while there was a
flight cap in place?

and it what legally binding agreement is a flight cap imposed?

--
Lansbury
www.uk-air.net
FAQs for the alt.travel.uk.air newsgroup

"Malcolm Weir" wrote in message


Los Angeles International Airport has FOUR parallel runways. It ain't
a big deal, despite what the doom-sayers claim.

Quite a few airports have four parallel runways, or more specifically, two
widely-spaced pairs of closely-spaced parallel runways. LAX is an example of
this, in quite a constrained, congested site, not unlike LHR. But Atlanta
has thr same layout and I believe thay're now building a fifth parallel
runway to the south. CDG also has four runways with this layout, though I'm
not sure if all four are yet operational. Even worse, Chicago O'Hare (ORD)
has five runways, which include two intersecting pairs of parallel runways
(http://www.oharenoise.org/Images/ord_alay.gif).

Cast_Iron wrote:
"MrBitsy" wrote in message
...
Aidan Stanger wrote:

snip

Another runway would have serious safety implications if there's a
missed approach on the center runway.

Rubbish!

They currently use one for takeoffs and one for landings - how would
the situation be any worse with a third runway?


At present if an a/c taking off need to divert suddenly they simply
turn away from the other runway's flight path.

If you have three working in parallel where doe the middle one go?

Straight on.....

--
MrBitsy

Nigel Pendse wrote:

"Malcolm Weir" wrote in message


Los Angeles International Airport has FOUR parallel runways. It ain't
a big deal, despite what the doom-sayers claim.

Quite a few airports have four parallel runways, or more specifically, two
widely-spaced pairs of closely-spaced parallel runways. LAX is an example of
this, in quite a constrained, congested site, not unlike LHR. But Atlanta
has thr same layout and I believe thay're now building a fifth parallel
runway to the south. CDG also has four runways with this layout, though I'm
not sure if all four are yet operational. Even worse, Chicago O'Hare (ORD)
has five runways, which include two intersecting pairs of parallel runways
(http://www.oharenoise.org/Images/ord_alay.gif).

Looks like seven runways on the map?

"Martin" wrote in message

Nigel Pendse wrote:

"Malcolm Weir" wrote in message


Los Angeles International Airport has FOUR parallel runways. It
ain't a big deal, despite what the doom-sayers claim.

Quite a few airports have four parallel runways, or more
specifically, two widely-spaced pairs of closely-spaced parallel
runways. LAX is an example of this, in quite a constrained,
congested site, not unlike LHR. But Atlanta has thr same layout and
I believe thay're now building a fifth parallel runway to the south.
CDG also has four runways with this layout, though I'm not sure if
all four are yet operational. Even worse, Chicago O'Hare (ORD) has
five runways, which include two intersecting pairs of parallel
runways (http://www.oharenoise.org/Images/ord_alay.gif).

Looks like seven runways on the map?

I think that this is the proposed layout after expansion.

Your car, at 183mph, has to contend with cars operated by distracted
drivers, drivers at 57mph, drivers who are drunk, pedestrians throwing
rocks from bridges, drivers who are making ill-considered judgements
about weather conditions, etc.

Well of course it wouldn't be safe to do 183 mph on an existing motorway,
they just aren't designed for it as you say. But neither are most of our
railway tracks.

However, we could build some new high-speed motorways, suitably aligned for
183 mph, with a minimum speed limit of 150 mph or something, and it could
well work.

Of course, if you got a blowout at that speed the results could be rather
interesting.

"Richard J." wrote in message
...
Cast_Iron wrote:

At present if an a/c taking off need to divert suddenly they simply
turn away from the other runway's flight path.

If you have three working in parallel where doe the middle one go?

The issue is not about a/c "needing to divert suddenly" but needing to go
around for another approach to land. If both the other runways have a/c
taking off at the time, I guess the middle a/c would fly straight ahead
until it was safe to turn under one of the other take-off paths. It makes
the circuit a bit longer, that's all. Presumably the problem has been
solved at Paris CDG and other multi-runway airports.

One of the three, at least, will be in use for take-off only. It ought to be
possible for the aircraft on the middle runway approach to turn towards that
other runway and do a circuit in that direction.

However at LHR the proposed third runway is a short one, and so presumably
will be used by smaller aircraft for both landings and take-off.
--
Terry Harper
http://www.terry.harper.btinternet.co.uk/

Well, the only method that we can be sure works is by price. A high price
will force users to judge how necessary their flight is. Just look at the
drop in traffic after congestion traffic, all of these journeys that were
"absolutely essential" or "could not be made any other way" were obvious not
essential enough to warrant £5 expenditure.



Yes but it still stands that a lot of things are un-neccessary and
cause damage. Especially drug taking, smoking and drinking. But I
don't see the liberals and enviromentalists trying to ban these three.