They explain how contrails form in upper levels. There are diagrams in there explain why planes seem to “shut off” the contrail and then restart them minutes later.
Shows that every chemtrail plane close up has the same number of engines that standard plane model has.
More contrails (engine exhaust) will be produced upon acceleration than during cruise. If an airliner wishes to gain altitude he will accelerate and subsequently produce more engine exhauset.
I live in a cold climate and now that it is cold, I can now see more exhaust being emitted from my vehicle. When I accelerate from a stop sign or stop light, there is more exhaust being emitted than when I attain crusing speed to the point that there is very little to be noticed........