unless they are spewing a nasty fuel additive.
Would anyone suggest that the only thing a jet plane releases is pure water vapor?
To insist that all the contrails in our skies are the result of benign passenger planes is naive. Obviously you have not done your homework, nor taken a critical look at the sky. Why would a passenger plane take a 90 or 180 degree turn mid-flight? Talk about wasting gas!
Something doesn't add up.