Adrian Tupper wrote in message ...
(Boltar) wrote in
om:



Well we finally agree on something. Nuclear power is a far mroe
realistic and reliable alternative to wind farms, wave machines etc
but its been killed off my green activists who couldn't tell you the
difference between and alpha and beta particle if their lives depended
on it. Ah well, as history has shown time and time again, humanity
seems to have to learn its lessons the hard way.

At the current rate of consumption you are probably right. Of course a
better alternative to all of these is not to use so much enerhy in the
first place. But that's a bit boring...

It is a better alternative but unfortunately you come against human nature
with that solution. Most people either
A) Can't make the mental link between what they do and pullution or
B) Don't care anyway.
How many times have you been in london at night only to see empty offices
with all lights blazing? It doesn't matter how many times people are companies
are told , they just don't listen, so IMO the solution has to be at the
power generating end.

B2003

Terry Harper wrote:
"Graeme Wall" wrote in message
...
In message
"Terry Harper" wrote:

We're not talking about a landing, but the need to "go round again"
if the landing has to be aborted. This is unlikely to happen later
than when the captain calls finals, when he will be a couple of
miles away from the threshold, at least.

Last time this happened to me (Dublin) we were over the threshold
when the pilot aborted. Apparently an Aeroflot plane had, quote:
'Got lost' and hadn't cleared the runway when expected to. We went
up in a straight line and much steeper than a normal take-off. I've
also seen go-rounds at Heathrow happen much closer than two miles
from threshold.

Strictly speaking, the decision to abort ought to be made before the
pilot goes to "full flaps", because that inhibits his ability to get
away again safely. When he does that, he's almost committed to
landing. Trying to climb away on full flap is not nice. You cannot
safely raise them until you have enough speed and altitude.

In reality, the decision to go around is extremely late - almost at the
point of touchdown. All aircraft are able to go around safely as they are
very light on fuel anyway. Go around in a modern jet is no more difficult
than pressing the go-around button. The plane will automatically apply the
correct power, raise the nose to maintain a safe climbout speed, leaving the
pilot to raise flaps at the correct speed.

--
MrBitsy

Terry Harper wrote:
"Graeme Wall" wrote in message
...

But if it is a choice between a not nice climb out on full flap or
mating with a Tupulov half way down the runway, I know which I
prefer.

If there is a Tupolev halfway down the runway, you should never have
got that far. I've done a full-flap overshoot in an Oxford, and
didn't enjoy it much. It took forever to get to a height where I
could reduce the flap setting, even with the wheels up.

I can imagine! Not a problem for a modern airplane.


--
MrBitsy

Terry Harper wrote:
"Graeme Wall" wrote in message
...

But if it is a choice between a not nice climb out on full flap or
mating with a Tupulov half way down the runway, I know which I
prefer.

If there is a Tupolev halfway down the runway, you should never have
got that far. I've done a full-flap overshoot in an Oxford, and
didn't enjoy it much. It took forever to get to a height where I
could reduce the flap setting, even with the wheels up.

A landing aeroplane at Heathrow has only got to be dalayed on the runway for
a very short time to cause the next aircraft to go-around. That go around
will nearly always be when the aircraft is over the threshold.

I once saw a lufthansa B737 go-around at Heathrow in the storm of 86.
Controller said a baggage container was reported to be blowing across 27L.
The 737 went around - the wind was so strong that he climbed a couple of
thousand feet before making a left turn - he was still over the threshold!

Same day a Swissair pilot reported his groundspeed as 56 knots on the
approach!

--
MrBitsy

In message , Boltar
writes

40 years ago we didn't have computer prediction, they basically were
working on guesswork. Aside from models theres the basic physics that
C02 is a green house gas and more CO2 = more trapped energy in the
atmosphere whatever effect that may have.
Whilst I have no problem with the fact of increased CO2, we don't yet
know if the increase allows a corresponding increase in uptake by
vegetation.
--
Clive

In message
"Terry Harper" wrote:

"Graeme Wall" wrote in message
...

But if it is a choice between a not nice climb out on full flap or mating
with a Tupulov half way down the runway, I know which I prefer.

If there is a Tupolev halfway down the runway, you should never have got
that far. I've done a full-flap overshoot in an Oxford, and didn't enjoy it
much. It took forever to get to a height where I could reduce the flap
setting, even with the wheels up.

Being sat somewhere down the back of a Ryanair 737 I didn't actually see the
aircraft (it was dark a t the time), just repeating the edited version of
what the pilot said once we regained altitude! We were extremely low, can't
have been more than 30 feet off the runway.

--
Graeme Wall
This address is not read, substitute trains for rail.
Transport Miscellany at http://www.greywall.demon.co.uk/rail/index.html

Clive wrote:

In message , Boltar
writes

40 years ago we didn't have computer prediction, they basically were
working on guesswork. Aside from models theres the basic physics that
C02 is a green house gas and more CO2 = more trapped energy in the
atmosphere whatever effect that may have.
Whilst I have no problem with the fact of increased CO2, we don't yet
know if the increase allows a corresponding increase in uptake by
vegetation.

Yes we do: it does (not directly proportional, but it is significant).
However, there is the problem of what happens when the plant dies, and
also the problem that vegetation only deals with CO2 near ground level.

"Aidan Stanger" wrote in message
...
Clive wrote:

In message , Boltar
writes

40 years ago we didn't have computer prediction, they basically were
working on guesswork. Aside from models theres the basic physics that
C02 is a green house gas and more CO2 = more trapped energy in the
atmosphere whatever effect that may have.
Whilst I have no problem with the fact of increased CO2, we don't yet
know if the increase allows a corresponding increase in uptake by
vegetation.

Yes we do: it does (not directly proportional, but it is significant).
However, there is the problem of what happens when the plant dies, and
also the problem that vegetation only deals with CO2 near ground level.

Not mush of a problem as C02 is heavier than 'air' and it all sinks to
the ground over time.

tim

JRS: In article , seen in
news:uk.transport.london, Aidan Stanger posted at
Thu, 25 Dec 2003 11:32:00 :-
Clive wrote:

In message , Boltar
writes

40 years ago we didn't have computer prediction, they basically were
working on guesswork. Aside from models theres the basic physics that
C02 is a green house gas and more CO2 = more trapped energy in the
atmosphere whatever effect that may have.
Whilst I have no problem with the fact of increased CO2, we don't yet
know if the increase allows a corresponding increase in uptake by
vegetation.

Yes we do: it does (not directly proportional, but it is significant).
However, there is the problem of what happens when the plant dies, and
also the problem that vegetation only deals with CO2 near ground level.

When the plant dies, another one grows. We do not, after all, want to
reduce CO2 to zero.

The atmosphere, on relevant time scales, is fully mixed.

To affect CO2 by 50ppm, which is a useful but not necessarily sufficient
amount, about 33 mg/cm^2 of dry plant is required; which is about half a
pound per square yard, or two-thirds of a kiloton per square mile,
including sea, ice, desert, city and all.


--
© John Stockton, Surrey, UK. Turnpike v4.00 MIME. ©
Web URL:http://www.merlyn.demon.co.uk/ - FAQqish topics, acronyms & links;
some Astro stuff via astro.htm, gravity0.htm; quotes.htm; pascal.htm; &c, &c.
No Encoding. Quotes before replies. Snip well. Write clearly. Don't Mail News.

Dr John Stockton wrote:
Aidan Stanger posted:
Clive wrote:
writes

40 years ago we didn't have computer prediction, they basically were
working on guesswork. Aside from models theres the basic physics that
C02 is a green house gas and more CO2 = more trapped energy in the
atmosphere whatever effect that may have.
Whilst I have no problem with the fact of increased CO2, we don't yet
know if the increase allows a corresponding increase in uptake by
vegetation.

Yes we do: it does (not directly proportional, but it is significant).
However, there is the problem of what happens when the plant dies, and
also the problem that vegetation only deals with CO2 near ground level.

When the plant dies, another one grows. We do not, after all, want to
reduce CO2 to zero.

When CO2 is continuously being released from the burning of fossil fuels
(and from animals, including humans themselves) there is no danger of
reducing CO2 to zero.

The problem is that often when a plant dies, the carbon is often soon
converted back into CO2 (or methane, which is worse). This would not
matter were it not for the extra CO2 from fossil fuels - we now need
even more plants to absorb it.

The atmosphere, on relevant time scales, is fully mixed.

What timescales do you consider relevant? The atmosphere does mix fairly
quickly, but I'd still expect the time it takes to be significant.

To affect CO2 by 50ppm, which is a useful but not necessarily sufficient
amount, about 33 mg/cm^2 of dry plant is required; which is about half a
pound per square yard, or two-thirds of a kiloton per square mile,
including sea, ice, desert, city and all.