What you need to know: Before Boeing’s North Line can build its first commercial 737 for delivery, it must complete a process called Low Rate Initial Production — a deliberately slowed startup phase where conformity airplanes are built for FAA review. Here’s what that process is, why it exists, and what it means for Everett’s aerospace economy this summer.

Everyone in Everett knows the North Line is coming. Boeing announced it. The Herald covered it. The hiring signs went up on Airport Road. The stories about new assemblers learning their jobs in Renton have circulated through the shops and the union halls for months.

But there’s a step between “the North Line opens” and “the North Line ships jets to airlines” that hasn’t been explained in plain terms: Low Rate Initial Production, or LRIP.

LRIP is the phase Boeing must complete before its new Everett factory can build commercial aircraft for delivery. It’s not a delay. It’s not a setback. It’s a required feature of the FAA certification system — and understanding it helps explain why Boeing is being so deliberate about the timeline for the most significant factory expansion in Snohomish County’s aerospace history.

What LRIP Actually Is

Low Rate Initial Production is exactly what it sounds like: production at a reduced rate, on purpose, during the early phase of a new manufacturing line’s operation.

When the North Line begins building 737 MAX jets this summer, it won’t immediately be producing at full speed. The line will first build what are called conformity airplanes — jets assembled specifically for FAA inspection to demonstrate that the Everett production process meets Boeing’s type certificate requirements. These are not demonstration aircraft. They’re real 737 MAXs built to production standards, but the FAA reviews them closely before approving the line to operate under Boeing’s production certificate.

“Once the North Line begins operation, the program will complete a process known as low rate initial production,” Boeing stated in its April 2026 North Line feature. “During LRIP, the build process is intentionally slowed to provide additional checks and make any adjustments to the production system to support standard flow times in the future.”

Jennifer Boland-Masterson, the production leader for the Everett line, offered a vivid way of thinking about it.

“It’s like running,” she said. “We know how to do it, and we’ve done it before, but we need to warm up our muscles. You don’t start with a marathon. You start with shorter distances and build up from there.”

The Role of PC700

Every Boeing production facility that builds commercial jets operates under a production certificate issued by the FAA. For Boeing’s 737 program, that certificate is known as PC700. Before the North Line can legally deliver commercial aircraft to airline customers, it must be operating under PC700 — meaning the FAA has reviewed the production system and confirmed it meets the quality and safety standards required to build certificated aircraft.

The LRIP conformity airplanes are the evidence package. They demonstrate to the FAA that the Everett line can replicate the same build process as Renton — same tooling standards, same inspection rigor, same assembly sequence, same quality outcomes. Once conformity is demonstrated to the FAA’s satisfaction, the North Line gets added to PC700 and can begin producing jets for delivery.

“Boeing will use the first set of airplanes built on the LRIP line to demonstrate conformity to the U.S. Federal Aviation Administration,” Boeing confirmed, “allowing the North Line to operate under Boeing’s production certificate, PC700.”

Only after PC700 coverage is established can the North Line be integrated into Boeing’s overall 737 MAX flow — adding production capacity for rates above 47 airplanes per month, the threshold beyond which Renton’s three lines are fully committed and every additional jet requires Everett’s output.

The Wing Transport Tool: Everett’s Unique Supply Chain Link

There’s one key difference between how Boeing builds 737s in Renton and how it will build them in Everett: the wings.

Boeing’s 737 wing fabrication happens in Renton. Rather than build duplicate wing tooling in Everett — an enormously expensive and time-consuming investment — Boeing engineered a solution: the 737 Wing Transport Tool. This specialized fixture carries partially completed wings approximately 30 miles north from Renton to Everett, where final assembly is completed on the North Line.

The Wing Transport Tool is a purpose-built piece of logistics infrastructure that doesn’t exist anywhere else in Boeing’s manufacturing system. It’s one of the more tangible indicators of how the North Line was engineered as a genuine extension of the Renton production system rather than a standalone factory.

The People Making It Happen

The North Line workforce is being built from three sources: newly hired employees, existing Renton teammates who transfer to Everett, and experienced Everett workers from the widebody programs (777, 767) who cross-train on narrowbody work.

All of them go through Renton first.

John V., a nearly 40-year Boeing veteran who spent most of his career on the 747, 767, and 777 programs in Everett, now serves as an FAA and customer coordinator for the North Line. It’s his first time on the 737 program — and even he is doing structured on-the-job training in Renton before his Everett assignment begins.

“This will be my first time working on the 737 program,” John V. told Boeing’s communications team. “But we are doing the training right. Even folks like me who have been around for a long time are in Renton now getting familiar with the program and the product before the North Line starts.”

Among the newest members of the team are Jaden M. and Alondra P., who joined Boeing in late 2025 as two of the first teammates hired specifically for the North Line. Jaden’s job on the floor is installing the dorsal fin in Flow Day 1 — the first station in the Everett assembly sequence.

“Opening a new production line is something special,” Jaden said. “So, we have to do it right. Training went smooth and I’m excited and ready to get home to our shop in Everett.”

The broader Boeing hiring wave — running at 100 to 140 new employees per week across the Everett campus in 2026 — is creating the workforce that will eventually staff the North Line at full rate. The IAM 751 Machinists Institute on Airport Road is one of the primary training pipelines feeding that workforce, offering accelerated instruction in the mechanics skills Boeing needs most.

What Happens After LRIP

Once LRIP is complete and the FAA has reviewed the conformity airplanes, the North Line transitions from a startup operation to a fully integrated production facility. That’s when the economics of the Everett investment start to show up in delivery numbers.

Boeing’s strategy is to use the North Line to build all 737 MAX variants, initially focusing on the 737-8, 737-9, and 737-10. CEO Kelly Ortberg has said the MAX 10 — the largest and most complex member of the family — will be built predominantly in Everett. With FAA certification of the MAX 7 and MAX 10 expected later in 2026, the North Line’s MAX 10 mission is on a timeline to become real in 2027.

That progression — from LRIP to conformity to full rate — is what turns the North Line from a construction project in a parking lot into the newest, most productive narrowbody factory on the West Coast.

For Everett, that’s a transition worth understanding. The city has been a widebody town for 60 years — 747s, 767s, 777s, 777Xs, KC-46 tankers. The North Line adds something new: a factory where narrowbody jets, the workhorses of global aviation, get built for the first time on Snohomish County soil.

LRIP is the warm-up lap. The marathon starts when the conformity airplanes clear the FAA, PC700 covers the line, and the first delivery jet destined for an airline’s fleet rolls out of what was, until recently, just an empty corner of the world’s biggest building.

Boeing’s North Line has been coming to Everett all spring. Now it’s almost here — and the process that makes it official is well underway.

Frequently Asked Questions

What is LRIP in Boeing’s production process?

LRIP stands for Low Rate Initial Production. It’s a deliberately slowed startup phase for a new manufacturing line where Boeing builds conformity airplanes for FAA review. LRIP lets Boeing identify and fix any issues in the production system before operating at full rate.

What is a conformity airplane?

A conformity airplane is a production aircraft built specifically so the FAA can inspect and verify that a new production line meets Boeing’s type certificate standards. These jets are built to full commercial production specs. Once the FAA confirms conformity, the line can operate under Boeing’s production certificate and deliver aircraft to customers.

What is Boeing production certificate PC700?

PC700 is the FAA production certificate that covers Boeing’s 737 program manufacturing. Any facility building 737s commercially must operate under PC700. The North Line must be added to PC700 — through the LRIP conformity process — before it can ship delivery jets to airlines.

How do wings get from Renton to the North Line in Everett?

Boeing engineered a specialized fixture called the 737 Wing Transport Tool to carry partially completed wings approximately 30 miles from Renton’s wing fabrication facility to Everett for final assembly on the North Line. This avoids the cost of building duplicate wing tooling in Everett.

When will the North Line start building jets?

Boeing has said the North Line will open “this summer” (2026) and will initially operate in LRIP mode, building conformity airplanes for FAA review. Full integration into Boeing’s 737 MAX production flow — adding capacity above 47 jets per month — comes after LRIP and conformity demonstration are complete.

Will Everett workers be building 737s for the first time?

Yes. The North Line is the first time Boeing has assembled 737 aircraft outside its Renton facility. Many of the workers — including long-tenured Everett widebody mechanics — are cross-training on the 737 program in Renton before transitioning to the Everett line.