Trails

[MikeSamuel]

Ok, this probably sounds like a stupid question, but what are the trails left behind by aircraft. It seems to only happen at high altitude, and jets I suppose. What are they made up of, and why do some planes have them while others dont...?
There has seemed to be more in the sky this week. Is that simply because there are more aircraft flying because of the holiday season, or is it weather/pressure related.

Thanks

Regards

Mike

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What does this button do? Oh :(

[AffirmBrest]

Ice crystals.

It's not only jets, any engine burning fossil fuels produces water and CO2 as exhaust (amongst other things). The water freezes = ice.

The occurence is weather related, in two ways:

1. The level at which contrails start to appear and remain in the sky needs to be below the average cruise level of jets. Don't quite know for sure what combination of environmental factors is required to create them tho'.

2. More people go on holiday in the summer, hence more aeroplanes, hence more contrails.

Anyone else?

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...proceeding below Decision Height with CAUTION...

[foghorn]

They're chemicals sprayed out of tanks which are secretly refilled from MOD trucks when the aircraft are on the ground. You only see the spraying at high altitude because that way they get maximum coverage.

It's all a part of a grand scheme by HM Government in association with the US Government, Jehovah's Witnesses, the AA and the Women's Institute to keep the population under control. All airline pilots receive training in spraying as a part of their type rating, but of course if they were to tell you about it, they'd have to kill you.

:) :) :) :) :)

[Flypuppy]

Beer is the antidote!!

Go to this website and tell the world what you know about Contrails http://teksphere.com/discus/messages/212/212.html?MondayMay1420010254pm

They asked for pilots opinions, so give them. ;)