The rising turn-time impact at Southwest Airlines

Southwest has upgauged from ~65% 737-700 to ~65% 737-800/MAX 8.  This change has significant implications.  Whereas the airline typically used to carry 143 passengers (assuming a full flight) on the -700s, it carries 175 on the larger airplanes (assuming a full flight).  Southwest has to process 22.4% more people per flight on the larger airplanes.

Herb Kelleher, co-founder of Southwest, frequently cited the 10-minute turnaround as a competitive advantage. Southwest Airlines famously claimed it could turn an aircraft (deplaning, cleaning, boarding, and pushback) in as little as 10 minutes in its early years. This was a cornerstone of its high-utilization, low-cost model.