Boeing marked another airplane development milestone today as thousands of employees celebrated the debut of the first 737 MAX 7 at the company’s Renton, Wash. factory.

The MAX 7 is the third and newest member of Boeing’s 737 MAX family to come down the assembly line. The jet is designed for up to 172 passengers and a maximum range of 3,850 nautical miles, which is the longest range of the MAX airplane family.

Technology improvements allow the MAX 7 to fly 1,000 nautical miles farther and carry more passengers than its predecessor, the 737-700, while having 18 percent lower fuel costs per seat.

The MAX 7 is also superior to the competition, carrying 12 more passengers 400 nautical miles farther than the A319neo, on 7 percent lower operating costs per seat.

“For our airline customers serving airports at high altitudes or remote locations, the MAX 7 is the ideal complement to their fleet. We look forward to demonstrating the incredible flexibility and range of this airplane,” said Keith Leverkuhn, vice president and general manager of the 737 MAX program, Boeing Commercial Airplanes. “This is the third 737 MAX family member our team has successfully introduced in just three years. That’s a phenomenal accomplishment and a testament to the dedication of the entire 737 team.”

The first MAX 7 will now undergo system checks, fueling and engine runs on the flight line in Renton. The airplane, the first of two MAX 7 flight test airplanes, will begin its flight testing program in the coming weeks.

The 737 MAX 7 is scheduled to enter service in 2019, following delivery to launch customer Southwest Airlines.

The entire 737 MAX family is designed to offer customers exceptional performance, with lower per-seat costs and an extended range that will open up new destinations in the single-aisle market. The MAX 8 entered service with customers across the globe last year, and the MAX 9 will start deliveries in the coming months. The MAX 10 was launched at last year’s Paris Air Show and is scheduled to enter service in the 2020 timeframe.

The 737 MAX is the fastest-selling airplane in Boeing history, accumulating more than 4,300 orders from 92 customers worldwide.