Boeing 737 MAX 10 reaches firm configuration

This means engineers now have all the design requirements in place for what will be the largest member of Boeing's single-aisle family.

"The steps we've taken to reach this point ensure the MAX 10 will be the most efficient and profitable single-aisle airplane the market has ever seen," said Randy Tinseth, vice president of Marketing, Boeing Commercial Airplanes. "We're working closely with our airline customers to deliver on the performance and efficiency benefits we've promised."

The 737 MAX 10, which will use a stretched fuselage that is 66 inches longer than the 737 MAX 9, now moves into the detailed design phase prior to the start of production. The airplane will carry up to 230 passengers, delivering 5 percent lower trip costs and 5 percent lower seat-mile costs compared to its competition.

The MAX 10 will soon join the rest of the 737 MAX family. The first MAX 7 rolled out of the paint hangar earlier this week and will soon start flight tests. The MAX 8 has been in service since 2017, already carrying more than 1.8 million passengers. And the first MAX 9 is scheduled to be delivered in the coming weeks.