Belfast Observer Skywatch - FedEx MD-11F with different coloured contrails 29th July 2015.

TEEJ

Senior Member.

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Sunset on 29th July 2015 - Belfast UK was 9:31PM

http://www.timeanddate.com/sun/uk/belfast?month=7&year=2015

Nothing unusual in seeing different coloured contrails. Unlikely to be different engine variants, but simply down to the lighting or the camera not accurately recording colours?


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Obviously the "sphere" is just light reflecting off the underside.

His video description claim


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Notice that he doesn't inform viewers of the altitude of the McDonnell Douglas MD-11. The MD-11 was up at 30,000 feet and nowhere near those dark grey clouds.

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Image of MD-11F, Serial N574FE

http://www.airliners.net/photo/FedEx---Federal/McDonnell-Douglas-MD-11F/2591140/L
 
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Mick West

Administrator
Staff member
Three-engined planes have far greater potential of unevenly lit contrails as there's a third trail above the other two. The sun is generally above the trails, so this third trail contributes a lot to the shadowing of one of the other two.

Notice where the sun is shining on this image, and where the trail is darker. Even here you can see the start of a different color. The lit trail is pinker, the shadowed trail is more blue/grey

Source

Similar:

Source.

A similar thing here, most apparent close to the plane

Source

And another with uneven lighting
 

TEEJ

Senior Member.
Thanks, Mick. I remember that different engines thread. I'm colour deficient (red/green) so thanks for pointing out the natural cloud colours.
 
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