Contrail or chemtrail ?

One of the constant debates online is whether the aircraft are leaving chemtrails or just the normal contrails that you would expect to see coming out of the aircraft engines as the hot air is cooled down rapidly in the cold dry climate at high altitude.
I worked on aircraft for about 30 years as an engineer so have some knowledge to bring to the subject. I've refuelled, serviced and flown in aircraft hundreds of times.
Contrails usually leave a trail that is about 6 times the length of the aircraft. It usually evaporates after 30 seconds or so. However in the last ten years I've noticed that some trails no longer evaporate and can follow the aircraft for miles across the sky. Eventually the trail spreads out across the sky and combine with other trails until there is just a cloudy mess blocking out the blue sky and more importantly, the sun.This is for aircraft flying at the same heading and altitude as aircraft that are still only leaving the conventional contrails.
 I watch aircraft that fly over on scheduled flights and if it's a clear day I can use them as a reference as to whether it's a contrail or chemtrail. Planefinder   will give you heading and height info etc so you can compare their contrails to aircraft at the same altitude leaving chemtrails. I can set my clock by an Air Berlin flight that is heading over the atlantic to North America. German accuracy has never changed !
There are also two Norwegian airliners that fly over twice a week on the way home from The Canaries. They are a good guide as they're about 5 minutes apart and on the same height and heading etc so can show a change in contrail for slight variations in atmospheric moisture. I've never seen them leave a chemtrail.
The aircraft that leave chemtrails look similar to conventional aircraft but will fly in criss cross patterns and occasionally double back on themselves. They're usually white although there are numerous examples on the web of various livery colourings. There can be about ten aircraft in the sky at the same time laying down the patterns. The most that I have seen flying side by side is 4 but they don't normally do this and fly in grid patterns as if trying to map out the sky.
I've taken hundreds of pictures and here are a few over Tayside...

Chemtrailer flies parallel to previous chemtrailer

one of these mystery white aircraft...rarely appear on planefinder website.

chemtrailer flies parallel to previous chemtrailer

white aircraft

criss cross patterns popular...don't know what ATC makes of it all.

looks like a darker livery on this chemtrailer

appeared to fly into previous chemtrail...masked up I hope ;)

right hand chemtrail ( laid earlier ) starts to expand

crissy crossy....boys and their toys !

headed for the centre of this small cloud.

flew above previous chemtrail

My main questions for the Contrail v Chemtrial debate would be.....

1. If they are just normal contrails then what have they done to the aircraft fuel to cause such long trails over the sky ? Up until ten years ago you rarely saw a contrail, never mind a chemtrail so something must have been added to the fuel to make them such a common occurence.

2.If the aircraft are just normal airliners then why do they fly in such dangerous patterns in the sky ? Going head to head, flying alongside each other  and doubling back on each other etc. If nothing else the passengers must be terrified. And the aircraft must use up excessive fuel. Something that airline companies normally abhor. Sometimes  flying as close to their fuel  limits as they can in order to cut costs.
And what does the Civil Aviation Authority (CAA)  in the  UK  or the FAA in the USA make of it all ? These  aircraft must be ignoring a myriad of rules and regulations.

3. If they are just normal airliners then why do they almost never appear on the tracking websites such as planefinder.net or flightradar24 ? I can look up at a chemtrailer laying patterns above my house but the sky will be totally empty according to the aircraft tracking websites.

Worryingly I've noticed that chemtrails are now being potrayed in the media as  'normal'. Most tv programmes and films now have them in the background without any comment about them. Kids at school are being brainwashed to accept ever more weird and wonderful chemcloud patterns as 'normal'. When I was at school we had to learn 4 or 5 cloud formations as they were the only one's we ever saw in the sky. Now there are dozens of 'normal' clouds to learn and a dimmed sky is 'normal' with  kids too young to remember the deep blue sky we used to enjoy when we were their age.
Our generation has the last chance to educate people that this new sky isn't 'normal'. It's abnormal.
I regularly get my old photographs out from the 80's and 90's and marvel at the deep blue skies and really 'normal' clouds floating in the background.
It's all very sad.