Crash Course

Southwest always had a lot to say about projected modifications to the 737, and Kelleher's team mostly wanted as few technical modifications as possible. With the MAX, they upped the ante: According to Rick Ludtke, a former Boeing employee, Boeing agreed to rebate Southwest $1 million for every MAX it bought, if the FAA required level-D simulator training for the carrier's pilots.

James Taylor-Foster
Source: Crash Course