Hi Watching the Skies,
Sounds like they must have very recently changed the structure of stage one, particularly this "aviation test", because that's the first I've heard about it on these forums. The basic checking hasn't been a part of stage 1 for a while now, it was replaced with the maths test quite some time ago, but otherwise the latest I'd heard is that the tests were all as you were expecting.
Sorry to hear that you feel you weren't treated very well. My experience over the past few months going through the selection process is that NATS have been nothing but professional throughout.