Boeing Fires Up a Fourth 737 Production Line — Its First Outside Renton in 50 Years

There’s no shortage of demand for the 737 MAX. Boeing has over 4,000 unfilled orders — enough to keep its assembly lines busy well into the 2030s — and the company is now racing to build planes faster. Enter the “North Line.”

IT-NEWS, July 15 — Boeing celebrated the opening of its new 737 assembly line in Everett, Washington, on July 10, marking the first time in more than 50 years that the 737 is being built outside the company’s Renton factory. Workers marked the occasion with a relay race and a ribbon-cutting ceremony, Boeing China confirmed Tuesday.

Until now, every 737 that rolled off the line came from Renton. The Everett facility — known as the North Line — is the program’s fourth production line, and Boeing poured $1 billion into it. It will focus on building the 737-8, -9, and -10 variants.

Renton is currently working toward a production rate of 47 jets per month. The North Line is designed to push total 737 output to 52 planes monthly, with room to scale further. That’s a significant jump for a program that has spent years under production caps and quality scrutiny following the 737 MAX grounding.

Boeing CEO Kelly Ortberg said the North Line will be “an important part of the 737 program’s long-term success.” The math is straightforward: with a backlog stretching past 4,000 aircraft, every extra plane per month matters.

The multi-site strategy also builds in resilience. Spreading production across two factories reduces single-point-of-failure risk, and Everett’s larger floor space gives Boeing room to handle more customized cabin configurations and interior options — a growing demand as airlines differentiate their fleets post-pandemic.