Repeat after me...
"Hello, this is Station Ops. How can I hinder you?"
Your ability to join into the Flt Ops Branch will depend on your ability to say "No" to aircrew in as many ways as possible.
Also, you will take part in an Empire Building Exercise and a further exercise whereby you see how many hoops you can hold up for aircrew to jump through.
Ignore the negative posts like above, and get used to aircrew wanting you to worship them etc etc.
The important thing in the interview is to be yourelf, and be honest. If you do not know the answer to the question say so.
Good luck