1. Jazzy

    Jazzy Closed Account


    The forewings of a canard aircraft suffer a higher wing loading than the rear wings so that near the stall the nose of the aircraft automatically lowers. That wing loading (when exploited sufficiently) will cause a sufficient pressure (and therefore temperature) drop at the tip vortices to form a temporary trail in certain atmospheric conditions.

    When the XB70 was lost (by one of its tailfins colliding with a Starfighter chaseplane) it went into a flat spin and a complete cloud formed above the whole aircraft as it fell.
  2. Mick West

    Mick West Administrator Staff Member

  3. FreiZeitGeist

    FreiZeitGeist Senior Member

    A Schoolar Poster about Contrails made by "Deutsche Zentrum für Luft- und Raumfahrt e. V. " (DLR) from the year 1989.

    (Dont´ be confused about the sligthly changed name behind "DLR", they had changed their name a little bit)


    I´ve searched a readable version for a long time , now i found it again...

    Last edited by a moderator: Nov 20, 2013
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  4. Mick West

    Mick West Administrator Staff Member

    Last edited: Nov 20, 2013
  5. Mick West

    Mick West Administrator Staff Member

    I was browsing in a second hand bookstore today and found this:

    Life Magazine, Nov. 29, 1943, pp 69-83.

    Looked it up when I got back. It was an air-force book, partially reprinted in Life.

    View attachment Target Germany.pdf

    Also has this small image:
    And mentions of vapor trails:

    There's also a video with the same name that seems to have some close-up shots of a contrail from above, as well as some conventional contrails video.

    Last edited: Nov 20, 2013
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  6. Tim TheToolman Coles

    Tim TheToolman Coles Active Member

    Very Nice catch Mick. :)
  7. FreiZeitGeist

    FreiZeitGeist Senior Member

  8. MikeC

    MikeC Closed Account

    I am not sure that this particular one is a contrail - for the few seconds it is in the video it sems to get smaller, which makes me think it might be a smoke marker.

    the following text explains how they were used:

    From here - http://goodsky.homestead.com/files/deception5.html

    Earlier in the video you can see smoke trails ending in bombed areas - these are very distince single trails, as opposed to smoke screens from the ground.
    Last edited by a moderator: Nov 20, 2013
  9. FreiZeitGeist

    FreiZeitGeist Senior Member

    These are two great ones...

    Number one: From the german Nazi-Propaganda Magazine "Der Adler", Year 1941, Number 6


    The title means "Skywriting at war" and the article discripes, how contrails are formed and that they could be used to find the Airplanes of the enemy.

    Number Two: Script of a Scientific Lession for "german Academy for Aviation-Science (1940)".

    The Article´s name is "Die Entstehung von Eisnebeln aus den Auspuffgasen von Flugmotoren"
    (The formation of icy-clouds due to Evapurations of Airplane-Engines)

    This is a more scientific analysis how contrails are made and under what conditions they stay permanemt. Compareable to the "Color of Clouds"-Book from 1972. Take a look to this graph, showing under wich conditions contrails are persistant;


    "Wolkenschweife" means "contrails".
    X-Axis is temperatur in celsius. Y-Axis is relative humidity.
    Black squares are Flligths without any contrail.
    Circles are Fligths with a short contrail under 300 meter
    "+"-Sings are Contrails between 300 and 1000 meters
    black circles are contrails longer than 1000 meters

    Some other captures from this early WW2-Paper:



    You can donwload the PDFs to both articles here:

    First Article:
    Der Adler, 1941 Heft 6, Über die Entstehung von Kondensstreifen

    Second article:
    Die Entstehung von Eisnebel aus den Auspuffgasen von Flugmotoren
    Ernst Schmidt, 1940, Deutsche Akademie der Luftfahrtforschung

    Somebody who has better english-skills than me should translate these documents from World-war-2.
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  10. Cairenn

    Cairenn Senior Member

    It would imply that if enemy planes were being able to follow the contrails back to their source, that they were Persistent and long lasting.
  11. Ross Marsden

    Ross Marsden Senior Member

    FreiZeitGeist, did you notice that the two photos on "page 21" of your Number Two have been cropped out of the top right photo on "page 160", your Number One?
  12. JFDee

    JFDee Senior Member

    I assume the article in the "Adler" magazine is based on the paper by Ernst Schmidt.

    Here is my shot at translating the interesting part in that paper (pg. 19 and 20). For references to "DFS", see Wikipedia

    The problem of sublimation and condensation in supersaturated layers low on nuclei could be solved only to a small degree. It seems however that supersaturated conditions without condensation and sublimation are not as frequent as A. Wegener has assumed. Some of the phenomenons observed by Wegener are likely to have been caused by influx of water vapor. On their high-level flights, the DFS is conducting experiments with injection of hydroscopic and non-hydroscopic nuclei in the upper troposphere. No unambigious results have been found yet. The experiments are suffering from the impossibility to measure water vapor saturation properly at low temperatures.

    Based on the experiences about cloud trail formation behind airplanes to date, the DFS has issued a leaflet for the battlefront. Slow planes are more likely to create cloud trails than fast planes. With short cloud trails, alternating between full and reduced throttle affords a certain level of protection. If long and persistent cloud trails are forming, climbing and gliding flight has to be employed in turns.

    The problem in question has further relevance with regard to conditions for ice accretion. Jaumotte has pointed out an interesting case which is associated with the phenomenons described here. Above a rain and hail cloud at around 5000 m altitude, a 6 to 10 cm layer of ice formed on a plane in an area that was entirely clear. The reported thickness of the ice seems exaggerated, however the incident implies that above the cumulus cloud there must have been a clear layer with high supersaturation which was made unstable by the airplane, causing rapid icing.

    This case closely resembles the accident of three Italian planes near Lucca. In 1939, on December 6th three planes of the Italian air force crashed due to ice accretion. The planes were part of a larger squadron flying at 3000 m altitude above the clouds, within sight of each other. The planes flying in the middle of the group were creating veritable snow clouds, more accurately ice cloud trails, when they passed between two towering clouds. The following planes crashed when they passed that area, quite obviously due to icing. It is likely that the cause has been heavy supersaturation prevailing between those two high-reaching clouds which was amplified and "triggered" by the preceding planes, so that the trailing planes suffered sudden and rapid ice accretion.

    These cases are showing how scant our knowledge is about the supersaturated layers which exist in the atmosphere, and how significant the experiments conducted to research the meteorologic conditions of the upper troposphere are with respect to the safety of aviation. However, major progress can only be expected once the problem of exact humidity determination at low temperatures is solved, by methods that can be handled easily.
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  13. Tim TheToolman Coles

    Tim TheToolman Coles Active Member

    I took some time this afternoon to translate the first one so that it was a bit easier to understand it. A bit rough but I gave it my best.
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  14. Cairenn

    Cairenn Senior Member

  15. Mick West

    Mick West Administrator Staff Member

  16. Cairenn

    Cairenn Senior Member

  17. Mick West

    Mick West Administrator Staff Member

  18. MsVickie

    MsVickie New Member

    ​These are chemtrails, [...]
  19. Mick West

    Mick West Administrator Staff Member

    Perhaps you'd like to explain why, and we can discuss it in a new thread?

    Maybe pick one photo and explain why you think it's a chemtrail.
  20. Mick West

    Mick West Administrator Staff Member

  21. Cairenn

    Cairenn Senior Member

    Some of the nice diffused ones in that second photo
  22. Critical Thinker

    Critical Thinker Senior Member

  23. Mick West

    Mick West Administrator Staff Member

    The original image:
    Approximate location of the image:
    Last edited: Nov 20, 2013
  24. frenat

    frenat New Member

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  25. hemi

    hemi Active Member

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  26. CbIncus

    CbIncus Member

    An example of a persistent spreading contrail from the book "Aeronautical Meteorology" by Matveev and Smirnov, 1955 (Part 1). The book can be downloaded here: http://u8239182.letitbit.net/download/19610.1bd4a7628d527952a0c1cf648576/192923.rar.html.

    Облачный след.PNG

    The translation of contrail chapter:

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  27. justanairlinepilot

    justanairlinepilot Active Member

    The pressure drop is over the top of the wing. Must be a typo or an error with the translation.
    High pressure moves to low pressure giving way to lift.
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  28. CbIncus

    CbIncus Member

    Thank you justanairlinepilot for pointing out this detail. I've checked the original source in Russian and there is told about the drop of pressure and temperature under the wing (I think the authors speak about engines). The drop above the wing is higher and this is the cause of airplane's lift.
  29. FreiZeitGeist

    FreiZeitGeist Senior Member

    Back to topic...

    Some early Contrail-Pictures from the GDR
    (German Democratic Republic, most known as "East-Germany")

    collected by Allmystery-User Mr. Q

    Postcard with a IL-14 used by "Interflug" until 1963, so this picture must be taken earlier


    Postcard showing the Mitropa-Hotel near Airport Schönefeld, taken in early 70s


    Some "Haarp-Clouds" Over Berlin Schönefeld from the 70s (Yes, the GDR seems to be very progressive in secret weather-warfar ;-)


    2 Postcards from West-Berlin from the 60s


  30. Mick West

    Mick West Administrator Staff Member

    [NOTE: This thread is JUST for posting photos and video, and immediate commentary on them. Off topic or long discussions will be deleted or moved]

    OT Posts moved to:https://www.metabunk.org/threads/1757-Weather-Modification-in-Wikileaks-Contrails-vs-Chemtrails-Etc
    Last edited: Nov 20, 2013
  31. CbIncus

    CbIncus Member

    A quote from an old Sovietic book called "Aeronautical Meteorology" by M. A. Babikov (1951). Unfortunately there's no photo in it, so feel free to move my post.

    PDF link: http://firstep.ru/library/TechnicalBooks/AviaMeteorology.pdf (page 27).

    The book has a misunderstanding of condensation and sublimation nuclei (the author writes about them as about two different things). It has been shown later that they are the same.
  32. CbIncus

    CbIncus Member

    Some images from Sovietic Cloud Atlas by Hrgian and Novojilov (1978).

    contrail_01. contrail_02.

    http://elib.rshu.ru/files/img-214103409.pdf (read pages 49-50)

    Translation of the caption:

    The trails (1, 2) which were probably formed 15 to 30 mins. before the photography was done expanded and now look like sheep skin; the trail (3) formed later and reminds a band in the sky. The cirrus clouds behind possibly developed from earlier trails. WMO Cloud atlas code: 200.

    It's a good evidence of "chemtrails" over non-NATO countries and their transforming to cirrus clouds.
  33. Ross Marsden

    Ross Marsden Senior Member

    Actually, condensation nuclei (CCN, cloud condensation nuclei) and sublimation nuclei (IN, ice nuclei) are different.

    There are cloud condensation nuclei everywhere in the atmosphere. This is why it is so hard to get water supersaturation in the atmosphere. As soon as conditions get to water saturation, the vapor condenses on the abundant CCN to form a cloud of water droplets.

    There are essentially no ice nuclei (sublimation nuclei) in the atmosphere. This is precisely why areas of ice-supersaturation can exist for long periods of time.

    In the Russian book, it would have been sufficient to say,
    It is misleading to say "without condensation nuclei" because these are everywhere in the atmosphere.
    • Like Like x 1
  34. Mick West

    Mick West Administrator Staff Member

    And CCN and IN are different because of their molecular structures. For water to condense or accrete on the surface it needs to fit the molecular structure. Different substances have surface molecular geometries that are better suited for either water or ice. Since ice is a crystal it's got more exacting requirements.

    There may be some confusion because ice clouds can form on CCN, but they form first as liquid water, which then freezes into a crystal form, which then acts as and IN, then accretes - not directly into ice. This is the dominant mechanism for contrail formation.
    • Like Like x 2
  35. Ross Marsden

    Ross Marsden Senior Member

    Yes, the liquid water comes from condensation from some process that brings the air to water saturation.
    In the case of cirrus formation, that mechanism is cooling by lifting; upward motion ahead of a front, in the vicinity of a jetstream (warm die of the core), convection.
    In the case of contrail formation the mechanism is mixing with hot, moist jet exhaust.
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  36. CbIncus

    CbIncus Member

    Thank you for this information! I've been searching for something like this for a long time!
  37. FreiZeitGeist

    FreiZeitGeist Senior Member

    Observation of a persistant Contrail from the Year 1919

    „Wolkenbildung durch ein Flugzeug“
    (in: Naturwissenschaften , ISSN 1432-1904, Vol. 7 (34. 1919), Page 625)


    Source: http://www.digizeitschriften.de/dms/img/?PPN=PPN34557155X_0007&DMDID=dmdlog408

    the most important parts in plain text

    ... translated with google:

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  38. Mick West

    Mick West Administrator Staff Member

    Translation to natural English

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  39. CbIncus

    CbIncus Member

    Two articles from Meteorological Dictionary by Khromov and Mamontova (1974).

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  40. TEEJ

    TEEJ Senior Member

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