Yeah, not too sure about the 50% hit rate people are saying is about right but even if it is, there are no tests other than passing the course that HR can give you. All HR are there to do are to test the wider population and fill courses with people who have a good chance of passing. I couldnt tell you after a 30 minute interview your chances of passing ATC course, because I cant test your skills that you will use in air traffic control in an interview, the only way to do that is...you guessed it, try air traffic control.
Anyway, the selection process for RAAF Pilot training is far more arduous and even that has something like an 80% attrition rate, it has such a high attrition rate because the job is hard, like ATC.
Something that you also cant test before training is how you deal with stress. A lot of people say to me when I tell them that I am an air traffic controller "I have heard that is a stressful job" so much that I am sick of it, but I had a think about it...acute stress (stress at the console) is something that people can either deal with well, or they do not. they either make clutch decisions under pressure or they do not, this can be assessed under simulation. What cannot; is dealing with the other stress ATC's deal with; that lingering stress that is there before you start work, and stays there somewhat after work. It is this stress that in my experience that destroys ATC careers, not being able to continue to deal with this stress that ends up getting the best of people. There are no tests for it, it just comes down to the person, some people might start experiencing this type of stress whilst still under training (at the academy) but find under field training, the accumulation of these stresses is too hard to deal with. Once again, this cannot be tested for, quite simply the road needs to be walked by the individual, and HR cannot be held accountable for these particular failures