Southwest has ordered 100 Boeing 737 Max 7 aircraft, with the first 30 deliveries scheduled for 2022.
The agreement between the carrier and the plane manufacturer ends Southwest's exploration of mixing its all-Boeing fleet with Airbus A220 planes.
As part of the agreement announced by Southwest and Boeing Monday, Southwest has converted 70 737 Max 8 orders to orders for the smaller Max 7. Southwest flies its Max 8 aircraft with 175 seats and will fly its Max 7 aircraft with 150 seats, the company said. The carrier also added 155 options for Max 7s or Max 8s for 2022 through 2029.
In total, Southwest now has 200 Max 7s and 149 Max 8s on firm order through 2031, compared with its previous order book of 30 Max 7s and 291 Max 8s.
Richard Aboulafia, an aircraft industy analyst with the Teal Group, said Southwest's conversion of Max 8 orders to the Max 7 fit with its point-to-point, high-utilization business model.
"They have always had requirements for smaller jets," Aboulafia said. "Part of it is they have a lot of thin routes, and part of it is they love frequency."
• Related: Pilots praise beefed-up FAA aircraft certification
Southwest has flown only 737s since it began operating in 1971. But the company had investigated adding the Airbus A220-300, an even newer plane than the 737 Max, which serves a similar market in terms of seat size and has a list price of $91.5 million compared with $99.7 million for the Max 7.
Aboulafia said that given Southwest's buying power and the depressed state of Boeing Max sales, the carrier probably got at least 60% off the list price for this order, though just how large the discount was isn't known. Max sales have suffered both due to depressed demand caused by the Covid-19 pandemic and the 20-month global grounding of the Max fleet that ended last November.
Boeing had 471 more civil aircraft cancellations last year than orders, as the troubles with the Max were compounded by a five-month suspension of 787 Dreamliner deliveries due to the discovery last year of manufacturing flaws.
Boeing, though, did get a boost for the Max program when United ordered 25 Max early this month for delivery beginning in 2023.
Alaska Airlines also increased its Max order size by 23 planes in December.