"Anyone who puts in the required effort and meets the standards set by NATS at each stage of the application process fully deserves their place on a training course."
Why?
The selection process is not there as an end in itself, it is an attempt to identify candidates who will pass the college course and go on to validate. NATS invests alot of time and money in its ATCO trainees and has a responsibility to take whatever steps it sees fit not to waste either. The selection process has to predict which candidates stand the best chance of success with very limited information. NATS does not owe anybody a chance no matter how hard they try or how badly they want to do the job.
"Surely this says that NATS believe the process isn't reliable enough, (that's a seperate issue)"
NATS are well aware that the process isn't reliable and it IS the issue, until the pass rates near 100% selection will need to be constantly reviewed.
"It seems extremely unfair to put people through what is a hard process when in fact they cannot ultimately be fully prepared as there is a secret final stage that is out of their hands."
You can never be fully prepared for a job that requires as much training as ours. The final decision will always be out of the candidates hands, no matter what the job and as for being a secret - you know about it don't you?
All that said, I do not think that comparing psychological profiles will help very much and I would be surprised if its results were allowed to over rule the selection committees decision.
Although this is far from a new idea it bears repeating. The best form of selection is to send all candidates to operational units and have them work as assistants for a year or so and only proceed to the college on the recommendation of that unit.