jock - long and hard, I refer to the aptitude tests of course!
Let me see, this was over a year ago so a more recent candidate might be more useful. Took about 3 hours to complete. The tests I remember:
1. ILS type test chasing two needles with a joystick for about 2 minutes. You get 2 or 3 goes and your score will improve.
2. Strange orientation type test where you had to figure left from right and upside down from right way up really quick.
3. Another ILS type test but 3D-ish. Very like the old Flight Sim 98 with a succession of red boxes in the sky you had to follow. Bit faster though. Again 2 or 3 goes.
4. Rows and columns of colours and shapes to be matched quickly. Hard to describe but remember making a total **** of the first go and got 10/10 on the second.
Then there was verbal reasoning. Given a passage of text about anything - could be political or historical or management stuff - and you had to agree, disagree or could not say if certain statements were true about that passage. Leave all your own beliefs at home for this one and use only logic based on the text.
Then numerical reasoning. Bit of a bastard this one. Given a pile of information (pie charts, bar charts, huge columns of figures) calculate in your head (no calculators allowed) the number of trees chopped down in Denmark on December 10th for the Copenhagen branch of IKEA. Do able but only just I found.
Then the personality test. I think this test is really trying to weed out the uncommunicative nerdy loner. 100 questions or so that ask about the same 25 things in different ways.
I was given the detailed results afterwards.