Why wouldn't they spread to cover the sky?
1. Because, as suspected in reference to CTs, they're merely adding Barium and other reflective/conductive materials at flight level, for numerous reasons (most classified with HAARP)
2. They're mixing chemicals 'in solution' at flight level, as can be seen with the naked eye - not painting the side of a house
3. Granted, not all contrails constitute 'chemtrails'; most researchers worth their salt are fast to make a distinction.
4. Apparently, unlike regular commercial overflights, CT flights don't require N numbers (as spotted and reported by numerous researchers - just threw this one in for fun).
I love this thread, because it proves scientifically that the technology to disperse - virtually anything - via air not only exists, but that it exists in sophisticated forms and for quite some time.
Granted the posted pics are all declassified, from airline texts, military journals, etc. Truth is we'll never see the classified applications (of which there can be many) - or at least not this easily.
If you doubt this, try getting hold of some pictures of the CIA's aerial dispersion of biological toxins over Cuban crop fields - this is a well documented program which flew dozens of missions trying to poison/sabotage Castro's economy, not only as being widely reported but it's also part of the Congressional Record. So go ahead, be my guest - ask the CIA for copies of their air reconnaisance photos from these missions if you'd like, with the expressed desire being so that you can publish them on your chemtrail-methodology debunking thread - just don't hold your breath.
So yeah, this is great. Please feel free to exhibit and talk about all the declassified applications of aerial dispersant technologies that you can - it merely bolsters the argument of CT enthusiasts and researchers as "proof in method".
If you want to hide something, put it in plain sight.