You'll sit down with HR, a panel of pilots and get a technical portion from one of our senior captains. It's pretty relaxed. At some point you'll be in a conference room waiting for your turn to visit with a particular interviewer. There will be an HR rep in the conference room with you as you hang out, drink coffee and eat snacks. This is still part of the interview.
It's pretty relaxed. Their goal is to get to know you; having you on edge doesn't help them do so. Hope this helps.