An airline would have an agenda and specific things they'd be looking for. Consultants such as emerald coast could help you prep for that, and I would strongly advise that. A key point...if they ask a question that could lead to discussion of a negative (either a background event or personality trait), do not treat it as a "confessional". Answer the question honestly, but use the most benign example available to you.
Tell us about a time you violated FARs?
- Tell them about when inadvertently violated sterile descending through 10K.
- Don't bring up that time when the demanding boss pressured you to make four approaches and finally land below mins.
What is your biggest personal weakness?
- Tell how you can sometimes be a perfectionist, or maybe like to talk to much.
- Don't tell them about how you procrastinate, resent management, etc.
A large corporate operation might have a sophisticated enough HR group to have a similar agenda.
A smaller operation probably just wants to meet you, shoot the breeze, and decide if they want to hang out with you on a trip.