There are no tests!! Here is how the day runs:
There are 3 exercises that you have to do, everyone will be split into groups and do these in a different order. When you arrive they take your height and ask you to strap into a crew jumpseat.
Then there is a group discussion, a BA presentation given by them, and finally a 2 to 1 interview. You do all 3 tasks, and in takes around 3.5 hours in total. Thats it!!
It is the best stuctured interview I have ever been to in that there is no 'knock out' phase, where only some are taken onto the 2 to 1 interview. They look at the whole picture. The hardest bit is the 2 to 1 interview, they will ask you lots of questions on your experiences. As long as you do your homework you will be fine.
Good Luck!