As suitcaseman and others have said it is fairly impossible to screw it up
they're just checking that you can actually hold a conversation with them and are sociable and articulate enough to deal with customers. At least that's what it was back in March anyways.
Expect questions about customer service, relocating to Germany, hobbies and interests, decision making, etc.
Face to face interview is also pretty informal with a panel interview meaning a whole panel of people meet with you. The technical exam is easy ATPL questions. I did hear that they're including a SIM ride from November onwards though. Maybe someone's done badly on type rating!
Regardless, it's pretty impossible to not get the phone interview right. If you're all so worried about it and worried about missing a phone call etc maybe you won't handle GA flying very well
- if your CV is good enough they'll call and others have said they leave voicemail so just call them back! No sweat
