These are not contrails

Have they switched to quickly dissolving trail variants or, more likely, do the trails disappear that fast because of the low humidity up in the air? Or, even more likely, were those trails intended to rub off the few natural clouds that are gone by now despite the complete absence of wind? These are no contrails, because there is no commercial route in these parts of the sky - I definitely know this because a) last year I worked right next to the TXL-airport, almost losing my ability of hearing due to starting and landing real passenger machines not leaving anything behind but NOISE, and b) My parents live next to/under the regular tracks, just a couple of kilometers from here. And again, these are no contrails from regular military planes because b)1) there have never been planes over this area at all, b)2) There is no military base even close to the city. b)3) Even if there were regular jets on duty, then why so many of them, and further, at the same time and location for months? Notice: they fly in heights that make it impossible to identify the machines although TXL is as close as 10km - maybe 6km airwise. With regular flights it is "easy peasy" to read the company labels about 2km from here. They really start and land there - without crapping the sky with extras.