Ask Captain Dan: What are the white trails behind planes? Our Resident Pilot Answers Flight Questions August 4, 2011

Toronto ON – Pilot Dan Baz is answering your flying questions here on the Cornwall Free News.


If you have a question about flying you can email Captain Dan or post below.


I have been fascinated by airplanes since my childhood years.  When I hear sound of an airplane I always look up at the sky to see if I can spot it.   Sometimes when I look high up at the sky I see a white trail behind airplanes.  Is that smoke ?  Question from Burt.


A  byproduct of the fuel combustion process in the engines is water vapour.  This water vapour comes out of the exhaust of the engines.  Under certain atmospheric conditions at high altitudes, the water vapour from the exhaust of the engines will condense and turn into a cloud.  As the airplane flies, this cloud looks like a white trail behind it. This condensation trail is also known as a contrail.

A bit more about Captain Dan:

Captain Dan Baz enrolled in Flight School at the age of 16.

He has completed studies in Aircraft Engineering and Master of Business Administration. He has been at the controls of many different types of aircraft, from single engine Cessnas to large intercontinental jets on global routes.

Over the last four decades he has flown thousands of hours up in the blue sky.

Best Western


  1. True enough, Dan. There are con-trails. There are water vapour trails. There are also chem-trails. The chem-trails are the ones that a lot of people want to know more about, since they make us sick and spread disease. Normally, when I focus my high power binoculars on planes producing chem-trails above Cornwall, I notice that the planes are white with no markings or insignia. They come from all directions. Sometimes there are several of them and they make grid patterns. Usually it’s overcast or rains the next day.

  2. I was wondering if the chem-trail conspiracy theorists would reply to this one. Can you say X-files?

  3. So how do you explain the widely photographed chem-trail grids, Reg? Would you admit that the phenomenon of long last trails exists? Why is it difficult to believe that a water vapour trail would hang in the sky without dissipating for hours? Reg, do you think there is such a thing as conspiracies? What would you call three guys planning to rob a bank? Would you call that a conspiracy? What would you call an office rumour designed to force someone to quit? If a garage owner asked his mechanics to charge for parts not used, would you call that a conspiracy? If some guys were planning to drive a plane, boat or truck into a building would you be willing to call that a conspiracy? If five people were planning to run a boat load of cigarettes across the river what would you call that? Just because you can identify something doesn’t mean you are a fool. Conspiracy is as old a habit as man. I did provide a few links. I hesitated to say anything earlier because what is the point of discussing science, logic or reason here? Lets laugh instead. I imagine a personal attack is due about now. To me, the photographs compare quite well to what I’ve seen.

  4. You don’t have to be a conspiracy theorist just to look up and observe what’s happening. I’ve seen four or five planes at a time making the grid patterns, at fairly low altitudes, right over my farm. Not so much in the last year or so, but a few years ago it was just about on every sunny day. The trails did not evaporate. They just spread out until the sky was completely covered by thick unnatural looking cloud.

  5. That was probably the OPP planes looking for grow-ops

  6. Somehow I don’t think the OPP were flying large numbers of jet planes all year round looking for dope plants.
    But, you never know….

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