For more than 50 years, the boarding process at Southwest Airlines was one of the most recognizable rituals in US aviation. Passengers checked in, received an A, B, or C boarding position, lined up at the gate, and then chose any open seat once onboard. It was unusual, sometimes stressful, and deeply tied to the low-cost carrier identity that Southwest had at the time. So in this video, we take a look at why Southwest Airlines had to quickly revise its brand-new boarding process, what went wrong after the launch of assigned seating, and why the fight for overhead bin space has suddenly become one of the airline’s biggest operational problems.