Jet Contrail

Discussion in 'Hangar Flying' started by Richard6, Dec 5, 2017.

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  1. Dec 5, 2017 #1

    Richard6

    Richard6

    Richard6

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    One day I noticed some jets, commercial I assume, make some great trails across the sky. Then I noticed that the nice smooth trail begin to "clump" up.

    Here is a photo of the trail.
    Jet contrail.JPG

    Anybody know what can cause this?

    Richard
     
  2. Dec 5, 2017 #2

    rbrochey

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    In a town not far from me they call those 'chemtrails'... they seem to be seen around black Friday and Christmas time. Some folks say they are created by the government to drift down on the population, people breathe them in, then can't help themselves and line up for sales at Wal-Mart. I' don't know if I believe that or not.
     
  3. Dec 5, 2017 #3

    Kyle Boatright

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    Wingtip vortices.
     
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  4. Dec 5, 2017 #4

    BJC

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    Going to Atlanta for Thanksgiving.
     

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  5. Dec 5, 2017 #5

    Derswede

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    Love your comment....I have had folks for years make comments on that, was out at the local airport 3 weeks ago getting some dual when a guy in the FBO area asked where was the tank for the mind-control chemicals on a 150. I told him that a guy would come out, move the airplane to the tanks, and fill them up before we flew. When the guy taxi'd over and fill the wing tanks, I thought he was going to explode...took 10-20 pics on his phone. Had a lovely time that afternoon doing as my Brit friend call "Circuits and bumps" while spreading mind altering drugs mixed with 100LL all over NE Alabama...

    Derswede
     
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  6. Dec 6, 2017 #6

    N659HB

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    At one time it was the Aurora project. Donuts on a rope, IIRC.
     
  7. Dec 6, 2017 #7

    DeepStall

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    "Crow" (person's surname) type of wake vortex instability, made visible by contrail
     
  8. Dec 6, 2017 #8

    pictsidhe

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    I was in the UK when that unpronounceable Icelandic volcano blew. All air traffic was grounded. I have never, ever seen such blue skies in Wales, I made the most of them spending a lot of time outdoors. When the planes started flying again, I watched the trails get painted on until the familiar grey sky was back in a day. South Wales likely has a LOT of transatlantic flies buzz overheard, but those trails melding into a grey cover must be having some influence on the climate.

    Edit. According to a news report at the time, it was the worlds first carbon neutral volcanic eruption. All the CO2 it billowed out was offset by the reduction in jet fuel used.
     
  9. Dec 6, 2017 #9

    narfi

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    All joking aside, I would be interested in seeing the real math behind that.........
     
  10. Dec 6, 2017 #10

    Kyle Boatright

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    Do Volcanoes produce/release signficant CO2? I assumed they were just spewing molten rock.
     
  11. Dec 6, 2017 #11

    Richard6

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    So the vortex comes and goes as the aircraft is flying at a constant speed and altitude?

    The displaced contrail seems to be at regular intervals.

    Why does this not happen more often? Only certain aircraft produce this interesting displacement under unusual conditions?
     
  12. Dec 6, 2017 #12

    Norman

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    The condensation in the tip vortices only persists for a few yards. The long condensation trails behind airliners are exhaust just like cars steaming on cold days. If you look closely you'll notice that near the plane the number of trails is equal to the number of engines. Farther downstream from the plane the tip vortices entrain the exhaust condensation into two trails.
     
    Last edited: Dec 6, 2017
  13. Dec 6, 2017 #13

    Norman

    Norman

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    I don't think the picture in the first post is Crow instability. Crow instability is actually quite rare whereas contrails breaking up into lumpy ropes is fairly common. Crow produces very well defined loops. I've only seen it once and ran inside to get my camera but by the time I got back outside the loops had already decayed into funny little quotation marks. There are many better pictures of it on the internet now
     
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  14. Dec 6, 2017 #14

    Kyle Boatright

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    To elaborate: It is wingtip vortices disturbing the normal contrails.
     
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  15. Dec 6, 2017 #15

    pictsidhe

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    Google is my friend: CO2 data
     
  16. Dec 6, 2017 #16

    Jan Carlsson

    Jan Carlsson

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    Chemtrails, it is real, and a lot of pilots make there living by spraying, hired by the goverment, chemtrails is the only thing that work on persons with thinhats. :)
    Dimmerskys
     
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  17. Dec 6, 2017 #17

    davidb

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  18. Dec 6, 2017 #18

    BBerson

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    I watched a Boeing fly over with binoculars. It looked like the engines contrail were close to the horizontal tail. So perhaps the tail wake has vortices. Perhaps in opposite rotation of wings. Eventually they spread and connect with wing tip vortex.
     
  19. Dec 6, 2017 #19

    pictsidhe

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    I like asking chemtrailers to look at airliners through binoculars and tell me why the chemtrails sometimes don't start until 100 yards behind the aircraft. I can sometimes hear the cogs in their brain grinding when I do that.
    Excuse me, I need to generate my weekly quota of ground level chemtrails with my clothes dryer now. On a nice cold morning, I can obscure a neighbour's house!
     
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  20. Dec 6, 2017 #20

    poormansairforce

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    That's the new airliner, BS101, owned by Treehugger Airlines. They have the passengers jump up and down in unison to flap the wings making it a carbon neutral flight.
     

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