It's a (underfunded) government industry - change often takes a lot of time in big companys, especially with their high demand to security and procedures. I'd

It's a (underfunded) government industry - change often takes a lot of time in big companys, especially with their high demand to security and procedures. I'd like to recommend the AVWeb series "Say again" series by Don Brown. It gives some insight in the last decades of the airspace controlling government industry and it's problems. Example: http://www.avweb.com/news/sayagain/182641-1.html http://www.avweb.com/news/sayagain/182641-1.html