I emailed HR for the reason why I failed stage 1, and it was due to 'spatial reasoning' those damn cubes, haha! In many ways it's a relief to find out it was due to that and my maths therefore must have been ok, so it time to train my brain with spational reasoning ready for next year...
but to those who would like to get the reason why they failed I'm sure if you write NATS a polite email they will atleast give you something to those that would like to know, cheers