Home » contrails » Why do some planes leave long trails, but others don’t?

Why do some planes leave long trails, but others don’t?

Some planes in the sky leave trails that persist and spread, and other planes, in the same sky, leave short-lived trails, or no trails at all.

These trails are actually called contrails, short for “condensation trails”.  They are not smoke from the engines, they are formed when the water in jet engine exhaust (and there’s quite a lot of it, like car exhaust on a cold day) mixes with wet cold air and condenses and freezes into ice crystals.  Contrails are actually a type of cirrus cloud.  When the air is wet and cold enough the trails can stay around for a long time, and sometimes spread out.

This difference between trails that fade away, and trails that spread, is often used as evidence of the “chemtrail” theory, which states that the longer lasting trails (or some of them) are being deliberately manipulated for some reason.  So you see helpful images like this.

But this is wrong. Contrails can fade away, and contrails can persist and spread. It depends on the air they are formed in.

Now there are two main reasons why some planes leave trails and some nearby planes do not.  The less common reason is that different planes have different engines.  Some engines will leave a contrail in the air where another engine will not.  Here, for example, are an Airbus A340 (maiden flight: 1991) on the left, leaving contrails, and a Boeing 707 (maiden flight: 1957) not leaving contrails. Both are flying at 33,000 feet (part of a German test to study contrail formation), but the exhaust of the newer engines of the A340 is at a lower temperature, and so makes contrails in a wider range of conditions*.

You can also get a similar effect with engines at different power settings, especially if it affects the exhaust temperature. This can occasionally be seen with high altitude refueling, when the plane being refueled cuts the throttle to near idle in order to separate from the tanker.

Contrails in a refueling situation turn on/off

But here’s the main reason why you see trails on some planes but not on others, and I’ll emphasize it, because although it’s simple, it’s also easy to miss.

The planes are at different altitudes.

Yes, it’s really that simple.  The reason that one plane makes contrails or makes contrails that persist, and the other plane does not, is that they are in different regions of the air.   For simplicity, let’s refer to these regions of air as wet air and dry air, although the differences are a bit more complex.

When the plane is in wet air, it makes a contrail.  In dry air, it does not.

Surely, you might object, they would have to be miles apart?  Well, no, and that brings me to another point I fear I must emphasize:

Wet and dry air can exist within a few feet of each other.

Consider, for example, clouds:

Inside the cloud it’s wet.  Outside it’s dry.  What’s the difference between inside and outside?  It’s a few feet.

Look at the bottom of those clouds, see them extend off into the distance.  They form a layer at a specific altitude. Above that altitude there are clouds.  Below it there are no clouds.  The difference between clouds and no clouds is just a few feet.

Now those are low altitude cumulus clouds.  Let’s look at high altitude clouds.

Again they are in a flat layer.  The difference between being in the layer and not in the layer is just a few feet.

This layering of the air into wet and dry layers is not limited to clouds.  Seemingly clear air also contains exactly the same kind of variation in layers.  This was very neatly illustrated by the recent launch of the Solar Dynamics Observatory.  As it ascended it did not leave a contrail, until it hit a layer of wet air, when it left a contrail that lasted quite a while, and then it went into dry air again, and no more contrail

So, if a plane were flying in that middle region then it would probably leave a persisting contrail.  If it were above or below it then it would not.

But, you may cry, the planes are at the same altitude.   Now you might even disagree with a “few feet”, and say the planes were too close for them to be in different layers.  I’d respond with:

You can’t tell how high a plane is

And you certainly can’t tell if one plane is at the same altitude as another.   These planes fly at 30,000 to 40,000 feet.   Let’s see what the visual difference is at around that altitude:

I took one image of a jet nominally at 35,000 feet. Then scaled it for 34,000 (102.9%) and 32,000 feet (109.4%). I think you’ll agree they all look pretty much the same. Especially as this is more zoomed in than you’d see with the naked eye, which would be more like:



If the planes are flying lower, then it’s still similar. If the top plane was flying at 20,000 feet, then the bottom would be at 18,285 feet, still nearly 2,000 feet apart, and looking pretty much the same to the naked eye.

And that is with the same model of plane, directly overhead, and right next to each other. A situation that almost never occurs. If the planes are different, or separated, or at an angle to you, then it is IMPOSSIBLE for you to tell the relative altitudes when they are high in the sky.  Just look at this:

Or from the ground, with the planes at 30,000 feet.


They look about the same height, right?  In fact, if they were not overlapping, you’d think the JAL plane was lower, as it seems bigger, hence closer.  But actually, the JAL plane (a B777) is at least 1000 feet above the DHL plane (an A300).

And look at some planes on the ground, where we know they are all the same distance from the camera. The differences in size are very significant:

So, a simple question gets a simple answer:

The planes leave different trails because the planes are at different altitudes.

See Also:
https://contrailscience.com/broken-contrails/ – Why contrails are often broken and start and stop abruptly.

Debunked: High Bypass Turbofans do not make Contrails [actually they make more] – A more detailed look at why modern engines make contrails in a wider range of conditions.

*(Edited 3/15/2015): when I wrote this article in 2010 I’d said that the newer more efficient engines produced “more water”, and while it’s true that the cleaner the combustion the more water is produced, the difference is negligible for the two engine types discussed. The key difference is the exhaust gas temperature, as explained in the more recent  Metabunk article

376 thoughts on “Why do some planes leave long trails, but others don’t?

  1. Heh says:

    Alright so it adds up.. Is it STILL not a problem? That’s all I need to know to know they’re playing with the skies

  2. John says:

    Believe me mate, i am working class. My dad is a labourer, and my mum works part time doing bits and bobs. But i worked hard and got myself into a favourable position. It sounds to me like you feel you are owed something? Maybe my tax contributions can pay for your sky high internet bills if you like? Anyway, this is off topic. But not nearly as off topic as religion!

    It’s no suprise to me that as a chemtrailer (which you can deny all u want, but you clearly are), you are also a bible basher. You are an absoloute sheep mate. Religion is for people who cant think for themselves. There was no jesus. There is no god. So stop hiding behind your false curtains of education, wealth, religion and chemtrails… Make your own luck, use your god-given brain and DO SOMETHING WITH YOUR LIFE. Because everything that is coming out of your mouth at the moment is irrelevant.

    Your not going to listen to a word of any of that, so lets take another approach;
    Lets say the government is spraying us with chemicals.
    Lets say they are poisoning us with flouride.
    Lets say the nwo want us all dead.

    Then why is the population growing?
    And we are all living longer?

  3. I grew up in a poor working class family in Yorkshire (not too far from Michael, in US terms). It’s really got nothing to do with the topic.

    Just because you believe you are being oppressed by the elite, it does not necessarily follow that they are spraying you with poison. You need actual evidence to believe that.

    Now you’ve been shown that contrails can persist and spread, does that change your opinion at all?

  4. John says:


    Yes those lines in the sky come from planes.
    But it is not an intentional act in terms of ‘playing with our skies’

    Contrails will form AND persist If the weather conditions MAKE it happen.
    Like on a cold day, the weather makes your breath visible.
    Its the exact same principle on a much bigger and colder scale.

    And you may have noticed that it rains after these contrails appear?
    That is not becase the contrails cause the rain.
    The perfect weather for contrail formation is just on the edge of an approaching rain front, so when you see lots of contrails, it normally means that rain is approaching anyway!

    However, contrails will also form without the rain front.
    So this isnt always the case.

    No1 is playing with the sky. Planes are just being planes up there. Taking people and things to places, unwittingly creating contrails.

    If you dont like the visual pollution, then that is a perfectly valid point of view. But there is no such things as chemtrails. As these contrails are just water vapour.

  5. Alexey says:

    I do not know in what part of the UK Michael lives, but today in our region the sky was changing the other way around. In the morning, there was a thick layer of cirrus clouds full of spreading contrails, but in the afternoon, the sky became brighter. Old contrails gradually dissipated, while new contrails did not persist. Now the night sky is clear. I can see stars, despite some mist forming near the ground.

    Compare for yourself the sattelite images of the UK taken at 11:50 UTC:

    and at 13:35 UTC:

  6. michael says:

    nonsence its having an environmental impact therefore needs to stop … the point is if you were correct.. persistant contrail is avoidable. Its impact on the environment is massive.. or certainly was summer gone.
    This is the main deal and anyone who has not observed it clearly has not noticed yet.

    The nature of the smoke coming out of that car at -40 did not behave like chemspray.. it did not expand and form a layer. The UK have admitted spraying sulphur dioxide as an experiment.. you have got to dig hard its very cleverly worded but its here. I know personally 100% from inside information that they are spraying chemicals but i do not know what they are as the person would not name them. I know the militry HAVE sprayed barium… i know they HAVE sprayed E Coli…….

    A lot of people who are posting chemspray videos and pictures are acutally posting contrails. They are just getting carried away thats all, one dude made a video saying vinegar moves them! There are crackpots out there i do not deny, It is a skill and a challenge to remain objective and to continiously be truthfull. I wont back down from practicing it thats why i would be no good bieing a politician… or a chemspray piolot.

  7. But car trails DO expand and form layers at -40. The only difference is that car engines are way smaller than jet engines. But enough cars together can create a layer of ice fog.


  8. MikeC says:

    Michael wrote:
    My line on the use of chemicals remains as speculation other than the FACT that our militray spray Barium, i know this to be fact.. [/quote]

    Cool – so what’s the evidence for that?

    Michael: “What about flouride in tap water…”

    Has nothing whatsoever to do with chemtrails or contrails as far as I know.

    Michael: “can you give me ANY scientific reason for it being there? Any evidence that it enhances your health?”

    there is a vast amount of scientific literature about its positive effects on dental health – you might not agree with it, but saying it does not exist doesnt’ really help your case.

    “Am i wrong when i say it is a by product of nuclear fuel ”

    Yes, you are wrong. http://en.wikipedia.org/wiki/Fluorite#Occurrence_and_production

    “and the government turn it into a product in order to dispose of it?”

    There are many ways it can be “disposed of”, including water fluoridation, other industrial processes, and dumping – se http://en.wikipedia.org/wiki/Fluorine. Water fluoridation uses only about 5% of production worldwide.

  9. michael says:

    @unicus wheres the evidence? @Mike c.. your bottom talking again we all know there are various forms of flouride its in the periodic table after all… but you are obvously not aware of its negative impact on human health. TOPICALLY it can be used BY DENTISTS to TREAT cavities… this is its ONLY use… there is no evidence anywhere that flouride can help prevent or treat cavities when it is ingested into the stomach! And indeed a rising mountain of evidence that its harmful, even collecting on the pineal gland causing premature pubecity in children. It IS A WASTE product and is no benefit at ALL to human health.. so why put it in.
    Am i changing the subject? Well.. when you wake up you will realize the connection.
    I talked about proof of current day spraying.. i cannot reveal my source because someone would get in a lot of trouble… but its enough for me. Previous experiments are all over the internet.. and ive already mentioned the sulphur the uk have sprayed.. but of course will not give details.

    Much of your work is confidential… you want all of my information ..but are only willing to give limited and focused information yourself….. you will not talk about the waste disposal system on your plane you will not talk about fuel additive and as previously mentioned you will not admit to haveing bugger all control over where you fly and when you fly, infact have you even even met your boss? Thats why you get paid big $$$$$ your a puppet….

    And i say YOU.. because YOU are one person… who keeps posting by different names to look more impressive wooohoooo check out that ip n mac! Der! Busted government troll whats wrong you ran out of chemspray? Which patented US formula will you use this week? And why would the US PATENT chemspray if it werent being used? Why would they be coming up with aluminium resistant seeds?

  10. captfitch says:

    Why would you claim that everyone on here is the same person when you yourself are not Uncinus or Myself or Greg? That doesn’t make logical sense. If you can comment why couldn’t anyone.

    Micheal- real quick- let’s pick one possible topic. Fuel additives. What is one very common additive that is used by virtually every jet and what are its uses? When would you NOT have to use this additive and how is it commonly added to the jet fuel?

    Please provide your answer.

  11. michael says:

    not everyone just some of the names… you answer a question with a question.. ive got nothing to hide .. you have. I dont have a boss… you do!!! And you simply cant answer… hahahahahahaha gnight

  12. captfitch says:

    But you won’t even bother to do simple research about even one of the theories you have. Meet me half way- look up common fuel additives and do some work. Once you bring something to the table I would be willing to divulge some info as well.

  13. MikeC says:

    Michael posted: And you simply cant answer…

    That’d be be cause there’s no actual sensible question.

    You say there’s evidence of stuff…but won’t say what it is…so how on earth do you expect anyone to “answer” it? In fact you don’t expect any answers because you know you don’t actually have any questions.

    Eg you say there’s no scientific evidence of the benefit of fluoride..and then a couple of posts later you say you know the benefits of fluoride – two-faced much?? Yes – I think so.

    then you go off into silly little rants – IMO you are a troll – you have nothing except a bit of an ego trip here getting everyone to jump to your tune for a while.


  14. captfitch says:

    Yeah- I hear ya. I think unless he begins engaging in rational descussion I’m bailing out.

  15. 2muchface2palm says:

    michael, i’m sorry to have to say it but your blaringly obvious failed mental processes (“you insist on logical consistency therefore you must be paid workers for the government or worshippers of satan or genocidal maniacs”) is all the proof anyone needs that chemtrails are persecution fantasies that make those who consider themselves powerless feel a little better.
    please wake up, there is no shame in realising all you believed is fantasy, in fact it’s what ‘enlightenment’ truly means.
    this belief is a dangerous delusion, there is no necessity to imply a satanic conspiracy or posit paid government agents posting on a website of basic well established physics.
    for someone to want to clear this issue up, is a basic urge that any sane person would feel when they see another suffering so much.
    and your religious convictions are so clearly motivated by vengeance fantasies. do you have no self-awareness at all?
    please learn. it’s not shameful to realise you don’t really know anything. it’s the first step on the path to wisdom.

  16. Don Gisselbeck says:

    For what it’s worth, I have seen ice fog from snowmaking guns persist for hours at Montana Snowbowl. It was exceptionally calm and in the single digits. There were sun pillars and sun dogs.

  17. John says:

    Thats pretty cool Don.

    But Michael has no idea what you are talking about, yet he claims you are a liar.

  18. John says:

    Does anyone else think it’s iroinic that Michael is calling everyone else “puppets”?

    How is it not clear to him that HE is the puppet, blindingly following anything he reads on the internet?

  19. SR1419 says:


    “sun dogs and powder hounds”…

    (Bridger bowl- but close enough 🙂

  20. StMichael says:

    Today i noticed suddenly an abundance of contrails, didnt analise them, it would be great to think the puppets were real people and it was water vapour… still a concern.. but anyway… i just got on with my day. Trying not to notice the fact that it looked like some of the particles were ‘falling’ away from the trails…..
    A very dry day, only very slightly more humid outside than it was inside.
    And driving home.. i glanse into a valley… oh its all powder white! Is it fog? Is it just a haze or a midst? Nope not at all.
    I dont like chemtrail theory it is not a hobby or a like of mine, i hate the F****** word! But what i hate moreso is the fact that you are so institutionalised and brainwashed you believe whatever programme they put in you! Now go and save some carbon and stop wasting my time and trying to confuse and unsettle people who have noticed your chemspraying. Government authorities use the same tactic in disguise every time… they make the people confronting them look stupid… or even drive them to insanity.
    Good job Christ gave me a SOUND mind. Sad job that you think Christ is a swear word. Repent whilst there is still time my son.

  21. SR1419 says:

    Sometimes the ice crystals in contrails do fall…

    they are called Fall Streaks or even a loose definition of Virga…

    here are some from Yorkshire:


    in this paper they actually measure them:


  22. captfitch says:

    The sad part is the only people you told about the white valley was us. I hope all those people who were sprayed are OK.

  23. Michael says:

    hahahaha sometimes ice crystals do fall they are called Fall Streaks or even a loose definition of Virga…bloody americans try to re invent everything.

    You absolute nerd! They are called hale stones or rain or snow.. now stop trying to reinvent science to try and incorporate chemtrails into natural cloud cover! As you are well aware the impacts of chemspray are cumulative and difficult to diagnose. But i can guarantee in the next 48 hours there will be lots of sneezing… right on pay weekend. It must be the ‘seasonal’ flue eh?

  24. GregOrca says:

    “hahahaha sometimes ice crystals do fall they are called Fall Streaks or even a loose definition of Virga…bloody americans try to re invent everything.”

    NO Michael. They are not a new invention. They were photographed and documented long before the invention of the airplane. Appearing in paintings from the 1400s and earlier BEFORE Columbus.
    The Word Cirrus itself means streak or fibre and was used by Luke Howard to specify high altitude clouds with that streaked appearance.
    Sailors for centuries have referred to Alto cumulus and cirrus uncinus clous by the saying “Mackerel scales and mare’s tails, make lofty ships carry low sails.” meaning that the presence of such streaky high altitude clouds foretells strong weather approaching.


  25. Michael says:

    oh how educational.. anyway what about the waste disposal systems on your planes, the fuel additives and changing of tanks? Have you inspected them lately? Or is it beyond the description of your job?

  26. GregOrca says:

    “oh how educational”

    Michael, interesting that you regard learning or education with barely concealed contempt.
    Would you like to share with us the reason for that?

    “Have you inspected them lately? Or is it beyond the description of your job”

    It might be helpful to refer to whom you are talking.
    My job is to do research and make film and documentary SFX and VFX. What’s yours?

    Do you know the meaning of the term “apophenia”?
    You might find that a useful concept to understand.

  27. Michael says:

    effects not FX. so this is why you know nothing about aircraft and chemspray, i see! Oh my mistake sorry where have the piolots gone? Or do you have a multiple personality dissorder?
    You should research HAARP… you wont find funding for it like… and if your into sound.. learn what radio waves do to particulate matter.
    Try it.. .maybe tip your speaker up… put some card on it and some sound… have a play… see what patterns you get in the sand… then have a look at the patterns in the sky on spraydays!

    Guess you best stick to murder sex and co2 if you want funding…Or do you only make what your told to make.. is it kinda like that.

  28. captfitch says:

    I know all about additives in fuel but you won’t even bother looking into the available info on the net. Until you ask a valid question about these additives I don’t know how our conversation can get started. I won’t address our waste sytems yet. Lets stick with additives. What’s the name of the most popular form?

  29. GregOrca says:

    It is unwise to try to correct the terminology and notation used by someone in an industry that you know nothing about. My industry uses the abbreviations SFX and VFX .

    Speakers use audio waves to move particulate matter , not radio waves. Speakers shift sand because an electromagnet mechanically moves a diaphragm that moves a mass of air. The kinetic energy of the vibrating air moves the particulate matter, not radio waves.
    Radio waves are inaudible.
    You seem to have missed basic science in your school years.

    Patterns in the sky like these?

    Why did you quickly try to change the subject from Virga/fallstreaks/mare’s tails?
    Do you think if you act like didn’t know anything about them nobody will notice?

    Michael, have you seen a counsellor of any kind to talk about your fears?

  30. Michael says:

    captishit… ive seen it all… i dont follow your links seen em all.. can you answer the question?
    The gregorca alias…. yea i worked in your industry for a couple of years….radiowaves are soundwanes.. tit…. there is an overlap.. oh cant be bothered with you.. its you that need to learn… go google haarp instead of harping on at me with your fabricated evidence and sick attempts at insult…. you really are a vile person i have no time for you…. bye illuminate see u on judgement day!

  31. SKYWATCHMAN (Michael) says:


  32. Michael, please use a consistent name. Attempts to pass yourself off as someone else will result in a ban.

    And you really need to address the questions, and not ignore it when some brings up something contrary to your beliefs.

    The link showed ripple clouds from over 100 years ago. Why would you ignore that?


  33. MikeC says:

    “adiowaves are soundwanes.. tit…. there is an overlap.. ”

    ROFL…..what an ignorant statement!!

  34. Noble says:

    “ROFL…..what an ignorant statement!!”

    That’s for sure..


  35. Freda says:

    All i know is that only in recent years have i seen so many contrails and aircraft have been around for ages. When i do look up in the sky there seem to be a hell of a lot of these ‘contrails’ and they do not go away but actually increase in volume and become massive cirrus type clouds.
    I understood that the minimum height for these contrails was 30,000 feet and apparently they appear much, much lower than that. You can actually see them criss crossing the sky in a checkerboard fashion as though they were being deliberately put there for some reason.
    Presuming they are vapour trails ,why have we not noticed them earlier, and why do they always last so long and spread to cover the whole sky. We used to get such clear blue skies and now its always messed up with these so called ‘contrails’. That sounds like the righy word for me. I am now certain they are indeed chemical trails and those people who get angry at the suggestion of chemtrails and contemptuous of others who say they are may well be people who have interests in Carbon Credits too.
    We often forget that if we are talking about ‘Global Warming’ that the Sun is the biggest and usually the one and only ‘culprit’. Why do people think that the Sun has always been the same?Why do they presume that climate always remains the same. Neither the Sun nor the Climate has ever been that ‘Constant’.
    Why on Earth do they think that human beings can solve such a Global Problem? Its outright arrogance to even contemplate it. Even if you got rid of all the CO2 it would not make an iota of difference.
    If people are going to make outlandish claims and base it on specious pseudo science then maybe they can tell the future? Do they put themselves into the category of fortune tellers too?
    Even the weathermen cannot give us a consistent accurate weather forecast let alone anything else.
    You can fool some of the people some of the time. some of the people all of the time, but you can’t fool all the people all of the time.
    I always trust my gut instincts and they say that All Politicians are Liars, and the General Public are
    Fools because they vote for them. The phrase ;”Follow the Money says where its at.
    Who was that person who once said they would tax the very air you breathe if you let them?
    Well Folks ; You have let them and you have believe the Liars.
    More Fool You and more fool the rest of us for allowing fools like you who believe in Chemtrails being Vapour trails to convince us. They are definitely Chemtrails and i don ‘t need some jumped up tosspot to tell me otherwise by blinding me with science.

  36. GregOrca says:

    “I understood that the minimum height for these contrails was 30,000 feet ”

    It is not true.
    Where did you get that idea from?
    Please have a read of all the articles on the left side of this page under the word “Articles”
    They deal with many different aspects of contrail formation such as ground level contrails.

    “Presuming they are vapour trails ,why have we not noticed them earlier’
    People noticed them over 70 years ago, that’s pretty early. Perhaps you mean you yourself have not noticed them. Lots of other people have noticed them and documented them in detail.

    “You can actually see them criss crossing the sky in a checkerboard fashion as though they were being deliberately put there for some reason.”


    Planes fly in different directions and their paths cross. Their paths thus form criss cross grids for the exact same reason that roads form criss cross checkerboard grids.
    Notice how roads look as though they were put there for some reason? Obviously It’s so people can drive from place to place.
    Flight paths are specified for the same purpose to fly from place to place but without you knowing about the enroute high navigation maps that specify those paths, you’ll only notice the paths if planes leave contrails.

    “they do not go away but actually increase in volume and become massive cirrus type clouds.”

    Yes, that is normal and has been documented as such many decades ago:
    ‪Extract from ”Flight To Arras” Published 1943‬
    ‪”The German on the ground knows us by the pearly white scarf which every plane flying at high altitude trails behind like a bridal veil. The disturbance created by our meteoric flight crystallizes the watery vapor in the atmosphere. We unwind behind us a cirrus of icicles. If the atmospheric conditions are favorable to the formation of clouds, our wake will thicken bit by bit and become an evening cloud over the countryside”.‬

  37. jwk says:

    Michael, when you lose your temper and go into a rant it probably indicates that you don’t have a sound basis for your opinions, and that you are feeling threatened by their arguments, and that you are “squirting ink” to hide that fact from both them and yourself.

  38. tryblinking says:

    No, I’m almost certain Michael is just trolling, to get an argument going for fun. There is no way someone could believe that sound waves of compressed air are somehow also a part of the electromagnetic spectrum overlapping radio waves. That would literally take a 10 year old 30 seconds to research and disprove.

    One of my favourites was in there though, the don’t try to blind people with science line. If the science is wrong, but sounds convincing, then that phrase applies. But if the science is right, then falling back on this defence simply advertises to all that you lack the expertise or perhaps juat the patience to understand it.

  39. HELIOMED says:


  40. HELIOMED says:

    I have been observing this these trails for years, i am a pilot and most of the logic explaining the con trails do not pan out.
    but i did not formulate an opinion either way, i just keep observing.

    My latest observations….i noticed that these trails occur only over certain countries, specifically NATO countries more than any other.

    Well, i live in Chicago and we just had the NATO conference that met in Chicago. So naturally i figured that if these trails persist in their normal fashion over the city like any other day…than they cannot be dangerous to our health ( as common sense dictates the NATO leaders would not be willing to breath in poison.)

    well, unfortunetly i am very disturbed at what i witnessed over the 3 plus days the Nato leaders were here.

    Zero trails over the city ALL 3 days. Oh yes they were visible downwind from the city one day and the next day even though the wind direction was opposite direction from the previous day, the trails were visible again downwind from the city.

    I did witness planes flying at altitudes of 30,000 plus over the city but only with a normal short vapor trail that disipates ina matter of minutes. Downwind from the city was a different story.

    Anyway, finally as i am driving i start seeing the trails criss croosing all over the city in their by now
    known pattern. about ten minutes later i hear a news report that the last NATO leader left the city at 4:30 p.m. and officially the NATO meetings are over. (By the way the trails started around 6:00 P.M.
    an hour and a half after the last leader left the city).

    Again, i still have not formulated a true opinion on what these trails are, but the facts to date are becoming more disturbing.

    I just wanted to share this information, as the pattern over those 3 days cannot possibly be explained by any atmosphere conditions or other wishful thinking.

  41. Why can’t it be explained by atmospheric conditions? The summit was in Chicago May 20-21st. 2012. Check the satellite images for those days for the big picture.


  42. HELIOMED says:

    Nice try….I have checked the satellite for those days and satellite does not distinguish a 100 mile radius or less because it is too small to notice. Satellite shows the big picture. However as i stated i did see the trails down wind. Also, satellite almost never gives you a picture straight from the top but usually in a angular fashion, therefore it is impossible to judge an area over a city where exactly the trails are.

    but my motion camera does not lie, and backs up what i stated earlier.

  43. Given the height of the satellite and the height of the clouds/contrails, the angle make very little difference to the relative positioning. But, these image actually ARE from nearly overhead, as it’s a polar orbit.

    The satellite photos I linked to also have 250m resolution image on the same page. You can clearly see it’s just the weather


  44. Alexey says:

    On flickr, there are thousands of photos taken in Chicago on those dates. Many of them show the sky with a lot of clouds, but there are a few old contrails as well, e.g.:


  45. captfitch says:

    HELIOMED is no pilot, at least not one that does anything above 10K. Too many common sense aviation knowledge mistakes in his post.

  46. Alexey says:

    Neither he [HELIOMED] is a very observant person. Here is a photo of a contrail right above the downtown Chicago taken on on May 20, 2012.


  47. Anonymous says:

    I am not a lunatic.(note the period) I have seen these conspiracy nuts before,and I still wonder.
    The explanations for contrails in this article are concise,but is it really that hard to believe that
    The u.s. government wouldn’t use every resource they have to test new programs and such?
    I trust facts.I don’t trust government.

  48. MikeC says:

    Not trusting the government is fine. And I’m sure they do tests of new programmes as a matter of course. But what new programme requires long white trails in the sky??

    Whether the government MIGHT do this is pretty much moot since there is no verifiable evidence of there being anything in the first place.

  49. Kat says:

    Wow, you guys have infinite patience. I stumbled across this site a couple of days ago and have been reading the very informative articles. Thanks for the info, a lot of which has actually been in the comment threads in response to contrail doubters and chemtrail believers. I look forward to learning even more. Kudos to you, Uncinus, for creating and maintaining this great site, and kudos to all the other commenters who are willing to share your in-depth knowledge and experience even with those who absolutely refuse to hear it.

  50. nodoudt says:

    Does anyone here ever think of the fact that, in order to spray a “chemtrail” for extended periods of time on long airliner flights, at the rate that a “chemtrail” is created, an enormous on-board liquid tank of some sort would be absolutely necessary to carry the chemicals? Not to mention the liquid, spraying equipment and so forth. For Goodness sakes people, does anyone EVER think about how much extra weight that would add to the plane?

    When a pilot performs a Weight and Balance on the airplane before EACH and EVERY flight, the weights of every single component on the aircraft are considered. That being the empty weight of the plane, plus passengers, luggage, fuel, etc. each constituting huge amounts of the aircraft’s useful load. If airlines had to carry the amount of chem juice to just spray for a few miles, they would be out of business because they wouldn’t be able to carry any passengers (all of the weight taken by the chem juice) So next time you get on the plane, ask the captain how much “chem juice” he’s got in the main and axillary chem tanks? We can only hope he’ll look at you funny and have someone escort you off the plane.

  51. captfitch says:

    all the pilots are in on it- remember?

  52. Kevin Carter says:

    Spraying us from Planes! What the hell! People really need to stop believing everything they read on the internet! If this is true can someone please answer the following

    1. Who’s paying for it and If it’s the governments why is the aviation industry one of the most taxed on earth? surely they would be doing “Favors”?
    2. Weight!!! Where on earth on a plane would you store the thousands of gallons of “poison”? Contrails can last for thousands of miles. Do most of you not know the size of of a fuel tank on a commercial airliner? You would need to double the size of the fuel tank to carry half it’s weight in liquid! It’s heavy stuff & who would be paying for the additional fuel? Doubt it’s the over taxed aviation sector?
    3. Aim! The waste would be incredible. To land a liquid from a plane from 30k ft on say an island the size of Hawaii you would need the marksmanship of Robin Hood! 30k ft, 300mph plane and 15mph ground winds and who would be “pressing the button” to activate spraying? Please don’t tell me it’s automated and the pilot would not notice anything that would just be farcical!
    4. Vitamin D! I’m from England if there was ever a case that you need almost 30 seconds of sunlight for your Vitamin D I’m living proof! We get 3 minutes a year in England and I’m fine with that! That’s why I use planes to get my fix!
    5. Last Question! Do you still believe that Diana was murmured by the Royal Family, That we never landed on the moon, that 9/11 was a cover up, that the illuminate rule the minds of all the worlds leaders, that gravity is a myth because you cant see it! The only reason you still don’t believe the world is flat is because you believe planes fly around it to “spray us”

    [Admin: edited slightly for politeness]

  53. AtleastIKTT says:

    Hughes Aircraft Patent #5,003,186. Must have been created by us “conspiracy theorists”.

  54. Danny says:

    There’s nothing quiet like breathing in the fresh zinc cadmium air. The UK Government have done it before, my friends 😉 They sprayed ZINC CADMIUM, Once you’ve read that go look up Zinc cadmium.


    Millions were in germ war tests
    The Ministry of Defence turned large parts of the country into a giant laboratory to conduct a series of secret germ warfare tests on the public.

  55. Thomas says:

    There are other reasons to believe the idea of government created chemtrails is not true. For one, if a government wanted to spread viruses, to dump them out of the air in 60 degree below temperature is hardly an effective method. The virus might quite likely freeze and die. Very few, if any, if they lived, would actually land near a person. Viruses need to be inhaled in a certain quantity in order to infect someone. The best way to infect people is by having an infected host walk through a crowded terminal, school room, for airborne viruses. Contaminating the water supply would be a much more effective way of introducing heavy metals or mind control substances into a population. As in the case of Fluoride, for instance. Controlling the TV, news media and Hollywood are highly effective and proven methods of
    “mind control” of a people, as we can see everyday. Why dump chemicals on them from 35,000 feet? Most chemtrails are seen over rural areas, where there is no population, so it would be a complete waste of time and money on the part of the conspirators. Control of the weather is another question. Is there any hard evidence at all that the weather can be changed using such high altitude methods? To what end? Can droughts be created? How? I fully believe there are very powerful groups of evil people who secretly try to manipulate the politics, economy and well being of the earth’s population. But “chemtrails” I do not believe are one of their techniques.

  56. MikeC says:

    Danny we HAVE all read about those test – do you rally think you are the first person to mention them here??

    Perhaps you would like to tell us how that “proves” that something is being sprayed out the engines of commercial airliners NOW??

  57. i luv to see planes with contrails.Planes are my heartbeat and everything,i can’t live without planes.I consider myself that m a this much big fans of this aviation world that noboddy can’t 🙂

  58. Matt says:

    People have been talking about dumping aluminum from the sky to modify the weather since the 1800’s. Today, fuel companies are investing in the decline of the Arctic since the Arctic pole contains over 1/4th of the entire worlds oil.
    This isn’t from conspiracy websites, it’s from weather.com, cnn.com, bbc, etc.

    There are videos of planes almost hitting these others jets that are dumping stuff.

    There’s also videos where you can see these ‘contrails’ being DUMPED.

    Also, the army already admitted to pouring chemicals in the air for weather modification. Though, they claim it to be a fix for global warming, they still admit to dumping chemicals..

    So this entire article, is wrong…

    People need to stop hating conspiracies and learn to read. A conspiracy isn’t a clique, it’s something that might actually be happening in this world.

    Not everything is a peach.

    You need to read about the military dumping chemicals on other countries to deprive them of food and vegetation. Dumping these chemicals in excessive amounts for almost 10 years at a time, leaving entire countries with deformities in their child birth and more.

    You really can’t say that when you look up at 7 in the morning with a blue sky, and watch jets come from one direction, over and over and over, until around 9am the entire sky is white from these jets and you can no longer see the SUN, that you believe these to be CONTRAILS?

    People are idiots for believing the better in life.

  59. Strawman says:

    And now please provice sources and evidence for your claims. Because so far, they are merely unsubstatiated claims.

  60. SR1419 says:

    Matt said: “entire sky is white from these jets and you can no longer see the SUN, that you believe these to be CONTRAILS?”

    Well, since we know that contrails can and often persist for hours, spread and cover the sky in a haze of cirrus cloud…why would we think it is actually something else?

  61. Chrs says:

    Well, I have heard and read about some chemtrails occuring in USA. The whole reason behind this was that many farmers complained that their crops are not growing so well anymore. High levels of different substences were found in atmosphere that have not been there before (if I remember correctly, one was aluminium dust). And the conspiracy behind this, is that the big seed corporation Monsanto is trying to control the whole farming industry. They pollute the air with chemtrails so that only their GMO seeds will grow in those regions that have been sprayed. As we know most seeds in USA already come from Monsanto but some farms still try to use 100% natural seeds and Monsanto is repressing them in every possible way. To me, this sounds quite believable and there is some proof to that if you google that topic. There is also a documentary that talks about this subject (Food Inc.).

  62. Chrs says:

    About military spraying poison and here is a link to the source:

    BTW these areas in Vietnam are still not able to grow plants. This poison was really “effective” so why not use it again?

  63. Chrs, aluminum would not affect crops, as the soil is already about 7% aluminum, see:

  64. Steve Funk says:

    “This poison was really “effective” so why not use it again?”
    Not sure what your question is. Of the two ingredients in Agent Orange, 2-4-5-t is no longer legal, but 2-4-D is still used and can be purchased at any non-organic yard and garden store in products such as
    Weed and Feed. It is used to selectively kill broadleafed plants, but not grass-family plants or conifers. It can still be aerially sprayed from very low-flying helicopters or crop dusting planes, as shown in your link, but this is regulated. They need a permit. This has nothing to do with chemtrails.

  65. Alynn114 says:

    Sigh. What a relief it was to stumble across your article. I sent the link to my husband, a chemtrail conspirist. How I dread the constant gazing at the sky and chemtrail comments. Why he doesn’t want to go outdoors because of the spray, why they never seem to spray when the president is in town. You may have saved my marriage! Now if only I could persuade you to write articles on how 911 really was a terrorist attack and a plane actually hit the pentagon, or even the latest conspiracy on how sandy hook was not staged to influence gun control; I’d really gain some sanity back. I suppose a recommendation for a good therapist who specializes in paranoid personality disorder wouldn’t hurt either. Also I wanted to commend you on the professionalism of your responses to the one particular writer. Wonderful display of intelligence and confidence. Kudos.

  66. Thanks Alynn, you might also want to check out my other site: metabunk.org

  67. nik says:

    I love debunking websites like this that totally ignore the data. Not once was the evidence of heavy metals in our rainwater and soil mentioned. Where is the mountain of aluminum and barium coming from?? Not once was FULL WING spraying mentioned, i.e.: United Airlines Flt#UAL877 witch has been modified to do this. Once you see full wing spraying commercial jets for yourself, then crappy websites like this are easily debunked. Try to explain this, Contrailscience! 2 engines, and the plane is spraying from wingtip to wingtip! Wake up, people!!!

  68. JFDee says:


    you may have overlooked this article which refers to the rain water tests of Mangels and others:

    Some more discussions here:

    What you are referring to as “full wing spraying” sounds very much like aerodynamic contrails.
    See this article:

    Search Google Images with ‘aerodynamic contrail’ for some exciting photography. There is nothing sinister about it.

  69. rahul singh says:

    Is this jet or airoplane??

  70. Rahul, I assume you mean a jet plane or a propeller plane. Normally it’s jets, as they fly a lot higher than prop planes. But prop planes CAN leave contrails, including persistent contrails, if it’s cold enough where they are flying. Prop planes in WWII left a LOT of contrails, as they flew very high to avoid anti-aircraft fire. There’s less reason for prop planes to fly so high now.

  71. Jason Munro says:

    I’d like some “scientific” explanation as to why some trails have no gap between the aircraft and the trail itself…. and don’t tell me it’s waist water. The heat from the exhaust on a normal trail will leave a significant gap, yet I’ve seen examples in which the trail comes directly from the aircraft. I’ve seen this happen for the entire visual expanse of the sky in which the aircraft is travelling. Am I supposed to believe that’s all waste water? None of the photos offered here as evidence show the trail coming directly from the aircraft, yet I’ve seen this on numerous occasions.

  72. Jason Munro says:

    What about the trails that come directly from the aircraft, without the gap caused by the heat of the exhaust? I’ve seen this on aircraft from one end of the sky to the other (funny, I don’t see any examples in the photos here), so don’t tell me it’s waste water. The plain would have to full of “waste water” tanks to cover the full visual spectrum of the sky.

  73. Jason, the gap is still there, just very small. It varies in size, see:


Comments are closed.