I did the aptitude tests at CabAir last Autumn. It consisted of a maths and physics exam, which you're given 1.5 hours each. I did both in about 25 minutes a piece, and scored 85 for maths, 78 for physics. All questions are multiple-choice and you're given a calculator and spare paper for workings out. My physics let me down a bit as I couldn't remember some of the formulas I knew back in school, (right-hand rule, etc.) Level is about advanced GCSE. Thankfully some the ones where you think "how the heck do I calculate that?" can be figured out by taking each of the answers in turn and working backwards.
The computer test is PilApt, and measures coordination and mental loading. It starts of with simple tests like where you control a wayward cross-hair, and builds upon them to the point where you'rehaving to do that while monitor coloured shapes and listening to a stepped countdown, and have to identify changes. It gets quite stressful, but anyone with a decent amount of computer game experience should be able to handle it.
I did well, my scores were well into the green and the evaluation was "minimal training risk", which was quite a confidence boost!
Si