The Best Video Evidence of a Chemtrail Plane, Shot by a Pilot close by

[DeDukshyn]

Posted by nearing (here)

Posted by DeDukshyn (here)
Very large long distance jets carry tons of fuel in their wings - they cannot land full of fuel or the wings would break off (well, it would just be extremely risky), so in the case of an emergency landing shortly after take-off, the pilot has to do a fuel dump. But in the video it didn't really look like this was the case? (emergency landing).

So only in emergency situations would this happen and at low altitudes?

Correct, but I'm not 100% sure all the regulations on fuel dumps, and I know there are some.