Phone screening first and they call you and ask your availability for an in-person interview at their office. The in-person interview was with three directors. I would say it is casual, mainly asking about your experience.
I applied online. I interviewed at AAR (Kabul) in Feb 2016
Interview
I Applied online was contacted by a third party recruiter was given a phone screen and then was told to expect a phone call on Saturday from the hiring manager and coordinated to receive a phone call from overseas manager in Kabul Afghanistan
I applied through a recruiter. The process took 2 weeks. I interviewed at AAR (Wood Dale, IL) in Aug 2017
Interview
The hiring process was a little all over the place. I kept getting rescheduled, but once I was in and did the interview it was quick and easy. It lasted maybe 30 minutes and I spoke with 3 different sets of people. They give you a tour of the building and Mike Amici in HR is AWESOME! Highly recommend speaking with him.