1. Tim

    Tim New Member

    On Saturday 13th June at about midday, I took this picture of an odd looking contrail overhead my garden just to the west of East Grinstead, Sussex. This picture was taken with my phone, but by the time I went back in quickly to get my proper camera, the trail had all but faded. This gave me the impression that it had happened very recently. I checked FR24 and could see no aircraft nearby that followed this odd route.

    trail.JPG

    I am aware that Gatwick is fairly close to my location, and I am also aware of the usual holding areas. However this trail would indicate that the trail was created at quite high altitude, well above normal holding areas. It also is quite clear that the pattern does not match the course for a normal holding pattern. If it did I'd be quite alarmed if I were a passenger on that plane!

    I did a bit of research, and one suggestion stated that "S-shaped" contrails could be vortex from large aircraft wing tips. Could that be the case here?
     
    Last edited by a moderator: Jun 15, 2015
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  2. Mick West

    Mick West Administrator Staff Member

  3. Trailspotter

    Trailspotter Senior Member

    Hi Tim, I'm very interested in this type of contrail. Could you please tell us the exact time of the photo, the direction in which it was taken and a general direction of this trail. There seem to be possible candidate flights, like, for example, this one:
    Screen shot 2015-06-15 at 15.44.25.
     
  4. Mick West

    Mick West Administrator Staff Member

    A couple of candidates that had just passed near overhead at 11:03 UTC (12:03 BST)
    [​IMG]
     
  5. Tim

    Tim New Member

    Thanks for the swift replies.

    I've just looked at the image properties from the photo, and it states Saturday at 15:19, so my estimate of the time seems slightly out; I thought it was earlier than that but I guess the image properties never lie!

    The course of the trail was an east-west direction. I can't tell which of the two was the actual direction as there was no trace of an aircraft and it seemed to be fading quite quickly. As I mentioned, I immediately went to FR24 and there was nothing nearby at an altitude that could have cause a trail like that. I've also looked at flight replays. My guess is that it can only be a vortex from an earlier flight? But then, the 'upward' strokes in the image seem fairly jagged - not very consistent at all.

    Thanks for the link to the discussion, I'll take a look

    Thanks again for the quick replies

    Tim
     
  6. Mick West

    Mick West Administrator Staff Member

    Can you also check the time on your camera, make sure it's real time?
     
  7. Tim

    Tim New Member

    Hello Mick - it was taken on my phone so I'm hoping the time is correct as stated on the image properties.

    Just took a sample picture again on it, and the properties are correct.

    Tim
     
  8. Mick West

    Mick West Administrator Staff Member

    So a likely contender is ABW602
    [​IMG]

    it would have passed over your house (10 miles south) at 14:09 UTC (15:09 BST)
    [​IMG]

    Google Earth track attached.
    Looking south from East Grinstead
    [​IMG]
     

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  9. Trailspotter

    Trailspotter Senior Member

    I had the same suggestion, but did not have time to explore it before going to a seminar. The green-blue spot in the photo is the Sun reflection in the camera(phone) lenses. Its position strongly suggests that the camera was facing south, pointing below and to the left of the Sun.
     
  10. Trailspotter

    Trailspotter Senior Member

    Yes, this is a contrail entrained in a single vortex. The wake vortices normally come in pairs and eventually cancel each other because to the Crow instability. In extremely rare cases, probably involving an atmospheric turbulence, the wake vortices may be decoupled by with one of the vortices surviving for longer and getting squiggly over the time.
     
  11. Tim

    Tim New Member

    Yes that's correct, I was indeed facing south at the time.

    Thanks for all the replies and explanation. I'll keep an eye out for more, but bearing in mind the speed it faded, I think that's probably not going to happen for a long while!

    Thank you all again
    Tim