In addition to what Redsnail has said, you will get asked a few scenario Qs such as what happens if the FO turns up smelling of alcohol, your passenger arrives with twice as much baggage as expected and to tkae it could put the ac over MTOM, that type of thing. I was told at the end of the screening that I had been successful and an interview was arranged there and then. My call lasted 15-20 mins. Good luck