Why do jets leave a white trail behind them.

Hi everyone,

Me and a friend are wondering why jets leave a white trail behind them. My
guess is that it's moisture being compressed as it passes through the
turbine (because some leave a single trail, while others leave two separate
trails). My friend thinks it's because of moisture being cooled as it
passes over the wing (Bernoulli effect).

While flying a bonanza I have seen a small white trail extending from the
wingtip for a little while right after I break through the clouds
(descending).

Is either one of us right?

AliR.

AliR,

Is either one of us right?


Your friend, partly. There are atmospheric conditions when the pressure
change over the wing or at a wing tip is enough to make the water in
the air visible. But they are rare and don't make long contrails. The
long contrails from jets you see are because the exhaust contains small
particles (soot and other stuff) which cause the water vapor in the air
to condense on them where it wouldn't condense without them.

--
Thomas Borchert (EDDH)

Don't forget that burning any hydrocarbon produces water vapor as well,
so the jet is also adding moisture to the mix. If the air is
relatively dry, the trail disappears rapidly, but if the atmosphere is
near saturation, the contrails can last for many minutes.
tom

"Thomas Borchert" wrote in message
...
AliR,

Is either one of us right?


Your friend, partly. There are atmospheric conditions when the pressure
change over the wing or at a wing tip is enough to make the water in
the air visible. But they are rare and don't make long contrails. The
long contrails from jets you see are because the exhaust contains small
particles (soot and other stuff) which cause the water vapor in the air
to condense on them where it wouldn't condense without them.

--
Thomas Borchert (EDDH)



How dare you promote the cover story that contrails are just water vapor and
exhaust. It is an operation by the CIA, FBI, NSA and Disney to poison us
all. You must be one of them.

OK I made up the Disney part, but you can read the TRUTH at the link below.


http://www.carnicom.com/contrails.htm

Oh it's called Contrails, I didn't know that. I found lot's of info on it
on the web. Thanks.

AliR.



"tom" wrote in message
ups.com...
Don't forget that burning any hydrocarbon produces water vapor as well,
so the jet is also adding moisture to the mix. If the air is
relatively dry, the trail disappears rapidly, but if the atmosphere is
near saturation, the contrails can last for many minutes.
tom

"Gig 601XL Builder" wrDOTgiaconaATcox.net wrote in message
...

"Thomas Borchert" wrote in message
...
AliR,

Is either one of us right?


Your friend, partly. There are atmospheric conditions when the pressure
change over the wing or at a wing tip is enough to make the water in
the air visible. But they are rare and don't make long contrails. The
long contrails from jets you see are because the exhaust contains small
particles (soot and other stuff) which cause the water vapor in the air
to condense on them where it wouldn't condense without them.

--
Thomas Borchert (EDDH)



How dare you promote the cover story that contrails are just water vapor
and exhaust. It is an operation by the CIA, FBI, NSA and Disney to poison
us all. You must be one of them.

OK I made up the Disney part, but you can read the TRUTH at the link
below.


http://www.carnicom.com/contrails.htm


Love the "How To Photograph A Chemplane" article...

It must be great to be able to get f/5 out of a 300mm f/4 lens with a 2x
teleconverter on it. Not to mention the detail you can get with ISO800 film
with your subject at FL330 !

LOL...

Jay B

In a previous article, "AliR" said:
Oh it's called Contrails, I didn't know that. I found lot's of info on it
on the web. Thanks.

Just beware of the paranoid lunatics who talk about "chemtrails".


--
Paul Tomblin http://xcski.com/blogs/pt/
Please say this was followed by a very serious discussion on Right and
Wrong involving a blow torch, 220V, a cobra and three East Germans
named Georg... -- Robert Uhl

Yeah, everyone knows Disney's mind control system is based in "It's a
Small World."

I ran into that, it was very funny.

AliR.

"Paul Tomblin" wrote in message
...
In a previous article, "AliR" said:
Oh it's called Contrails, I didn't know that. I found lot's of info on
it
on the web. Thanks.

Just beware of the paranoid lunatics who talk about "chemtrails".


--
Paul Tomblin http://xcski.com/blogs/pt/
Please say this was followed by a very serious discussion on Right and
Wrong involving a blow torch, 220V, a cobra and three East Germans
named Georg... -- Robert Uhl

Gig 601XL Builder wrote:
"Thomas Borchert" wrote in message
...
AliR,

Is either one of us right?


Your friend, partly. There are atmospheric conditions when the pressure
change over the wing or at a wing tip is enough to make the water in
the air visible. But they are rare and don't make long contrails. The
long contrails from jets you see are because the exhaust contains small
particles (soot and other stuff) which cause the water vapor in the air
to condense on them where it wouldn't condense without them.

--
Thomas Borchert (EDDH)



How dare you promote the cover story that contrails are just water vapor and
exhaust. It is an operation by the CIA, FBI, NSA and Disney to poison us
all. You must be one of them.

OK I made up the Disney part, but you can read the TRUTH at the link below.


http://www.carnicom.com/contrails.htm

I kept asking the 'chemtrail' kooks where I had to look on the aircraft
I fly to find the 'chem tank and the spray nozzles'
ROTFL