Boeing marked a milestone as the first 737 MAX 9 made its debut in front of thousands of Boeing employees.

The 737 MAX 9 is the second member of Boeing’s industry leading 737 MAX family, with a maximum capacity of 220 passengers and a range of 3,515 nautical miles.

The airplane now begins system checks, fueling and engine runs on the flight line. Once completed, the airplane will begin flight testing in the coming weeks – the final phase of verification of the operational characteristics and overall performance of a new airplane.

“The 737 MAX team continues to do a fantastic job getting us to these important milestones right on schedule,” said Keith Leverkuhn, vice president and general manager of the 737 MAX program, Boeing Commercial Airplanes. “Our primary focus is delivering an aircraft that has the legendary reliability our 737 customers depend on, plus the optimized flexibility and range capability they desire.”

The 737 MAX 9 is scheduled to enter service in 2018. The 737 MAX 8 is on track to deliver to customers in the second quarter of 2017.

The 737 MAX family has been designed to offer customers exceptional performance, flexibility and efficiency, with lower per-seat costs and an extended range that will open up new destinations in the single-aisle market. The MAX 8 and 9 will be followed in 2019 by the smaller MAX 7 and higher capacity MAX 200, while studies and discussions continue with customers on growing the family.

The 737 MAX is the fastest-selling airplane in Boeing history, accumulating more than 3,600 orders to date from 83 customers worldwide.