Question Question about aircraft vapour trails

[T1234]

In the morning on a cloudless day,the sky is blue but as the day progresses it fills with lots of lines that fill the sky then dissapates into a flat cloud that makes the sun dimm. It happens about 4 times a week where I live.
There is lots of talk on the net that there is a arosol spraying operation going on but I am not sure about that. Are there any aviation experts or knowlagable folks who could fill me in?

 

[george7378]

Definitely not aerosol spraying - it's only water vapor from the burned fuel condensing when it hits the cold air. Basically, just a normal cloud, created artificially.

 

[garyw]

Water vapour in fuel expanding in the thin atmosphere of 35,000 ft and freezing due to the cold.

There is lots of talk on the net about elvis being an alien, lots about fake moon landings (and not fake moon landings but we stopped due to aliens) and even more weirdness.

Anyway, About a minute in to this video you'll see the beauty that is a contrail (condensation trail):

 

[Urwumpe]

There is lots of talk on the net that there is a arosol spraying operation going on but I am not sure about that. Are there any aviation experts or knowlagable folks who could fill me in?

As Internet expert I can tell you, that using the Internet and publish texts has become so easy, that even idiots can do it.

Still, all is just the usual conspiracy theory nonsense, the only case in which aerosols are intentionally (aside of any combustion engine exhaust being an aerosol) by spraying them into the air at higher altitude (not crop dusting, which is also aerosols), had been the tests on the US Stealth aircraft for suppressing the formation of contrails.

Not used today, but the B-2A had such equipment installed during the prototype phase. The tests had not been successful, the chemicals made the contrail less visible for a short time, but had been much more visible on weather radar. The aircraft designers found out, that a simple lightweight sensor at the aft end of the aircraft, that warns the crew if they produce contrails, so they can change the altitude and fly into warmer or less humid air, is lighter and cheaper...and does actually work.

http://www.airspacemag.com/flight-today/Flight_Lines.html

 

[T1234]

Am I correct in thinking that the colder the air,the longer the trail,so the higher the flight path the vapour stays frozen for longer before it sinks?

 

[boogabooga]

The most dangerous aspect of the internet, aside from criminal activity IMHO, is that it allows nonsense, paranoia, and delusion to compete on equal footing with truth, facts, and reality. What we're left with is truth by consensus.

 

[Urwumpe]

Am I correct in thinking that the colder the air,the longer the trail,so the higher the flight path the vapour stays frozen for longer before it sinks?

No, the contrail does not sink, it moves with the wind. Also colder is one factor there, but also important is relative humidity. In dry air, the water evaporates faster. Over time, the water evenly spreads out in the air.

 

[Screamer7]

In the morning on a cloudless day,the sky is blue but as the day progresses it fills with lots of lines that fill the sky then dissapates into a flat cloud that makes the sun dimm. It happens about 4 times a week where I live.
There is lots of talk on the net that there is a arosol spraying operation going on but I am not sure about that. Are there any aviation experts or knowlagable folks who could fill me in?

What color are these lines?
If they are white and the clouds are white, it is just plain ice crystals.
But if they are black or brownish, it is global warming in the making duo to the exhaust smoke of these planes.

 

[Spacethingy]

Definitely not aerosol spraying - it's only water vapor from the burned fuel condensing when it hits the cold air. Basically, just a normal cloud, created artificially.

Tosh and piffle. It's a plot by the enemy governments to bring down the country with a combination of wet washing and a collapsed barbecue industry. :lol:

But seriously, I never knew it was H20 from the jets. You learn something every day!

 

[dgatsoulis]

Kinda relevant to this thread, on the trailer of the new Superman movie (1:07), it shows him creating a sonic boom and then flying upwards with contrails comming out of his boots(!?) :shrug:

I guess this is Hollywood's idea of a "realistic" superman flight. :facepalm:
Or is he spraying us with something?

 

[Evil_Onyx]

Here is an example of aircraft making short lived clouds, these are made by pressure changes in humid air. My understanding of how these are formed is limited, but i understand that as the air pressure drops the water in the air condenses becoming a visible vapor. so this forms after the bow wave (is it a shock wave at sub sonic speeds?) of the aircraft.

 

[T1234]

This vid offers a rational explanation.

http://youtu.be/pQz3aZtbF-c

 

[george7378]

Also, some other cool airplane clouds to watch out for - sometimes vapour can form in the engines, above the wings, and at the wingtips (usually during takeoff and landing), all due to pressure changes as the plane lifts and pulls itself.

 

[FADEC]

There is lots of talk on the net

, with lots of people involved who have no clue of what they talk about. The result often is a conspiracy theory.

[ame="http://en.wikipedia.org/wiki/Contrail"]Contrail - Wikipedia, the free encyclopedia[/ame]