Plane Answers: Airliners passing closely (with video) and how are tailwinds figured inflight?

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Reader Comments (Page 1 of 1)

4-21-2009 @ 9:10AM

nzm said...

Great video, Kent! Taken with the 5D MkII or your little Flip Mino?

I have a question on the contrails.

Over recent years I've done a LOT of air travel and spent many hours staring out of aircraft windows to spot other aircraft - I love to do so! I can only remember seeing black contrails from military aircraft in the past - mainly propeller-driven aircraft.

However, in recent months while flying routes between Iceland, Zürich, Berlin and Barcelona, I've noticed a lot of black contrails like some of the ones in your video - and emanating from commercial jet aircraft. I've never seen them before in such numbers.

What causes the black trails? Is it dirty fuel or badly maintained engines?

(BTW - my Google searches have led me to all sorts of websites claiming that contrails are chemicals being deliberately sprayed to control humans or weather-controlling experiments!)

Would love to know what causes the black trails!

cheers
Michele

http://mandjadventures.blogspot.com/

4-21-2009 @ 11:35PM

Kent Wien said...

Thanks Michele,

It was the Canon 5D Mark II. I'm loving that camera.

The dirtier contrails come mostly from older 727s and even MD-80s to some extent. Certainly the B-52 would qualify. The brighter contrails happen whenever there's enough moisture in the air to produce the "condensation trails." You must have been flying on one of those days, as I was on the day this video was shot.

I checked out the conspiracy theories on the chemtrails. Thanks for the entertainment!

4-22-2009 @ 9:30AM

nzm said...

Thanks for your reply, Kent. You've been most diplomatic! At about 43s into your video, you also have a dirty-trail 747 - I guess that it's also probably an older model!

I'm also loving my 5D MkII. I've been in photography-related industries for over 25 years, and it is the first DSLR that I have deemed to be worthy of buying - save for the 1Ds which are out of my price range!

I was amused by the "chemtrail" conspiracies too! There's one voice in the darkness attempting to explain the theory of contrails and he does a damn good job: http://contrailscience.com/ but the other side don't/refuse to/won't get it!

4-22-2009 @ 9:42AM

Kent Wien said...

Love your blog, Michelle. Looks like we both picked up the 5D at the same time. I'm still learning...

The 747 has rather 'modern' turbofans, so they just put out a larger condensation trail. I'm sure there's a fair amount of exhaust mixed in there as well.

It's interesting to see the contrails fan out over time and turn into something that looks like a cirrus cloud, hardly recognizable as a contrail. It seems www.contrailscience.com has done a great job countering the other sites. Thanks for that.

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