I know but this is why im loocking for an addon that can add this to my flight sim experience.
Just downloaded and saw the dangerous skies video and I see what you're talking about, the realistic wavey ones on the wingtip of a 747 in 48 to 51 seconds section of the video.
Tonite I will fly the UPS MD-11 and compare it, the UPS MD-11 doesn't appear wavey like that contrail in the dangerous skies video.
Best way to find out is to download that aircraft and see if it comes with that effect file.
The website where the video was made is at:
http://www.arkitekt.moonfruit.com/I already emailed them asking where did they download the aircraft or the vortex contrail effect file.
Hopefully they will have an answer.