Boeing’s 777X flagship remains key to the company’s long-term business strategy, and ensuring that the big twinjet is primed for a smooth delivery ramp-up by late 2023 has taken on critical importance as the manufacturer strives for production stability.

While the company works to earn the confidence of regulators to begin certification testing, Boeing is making the most of the delays to perfect assembly of the new twinjet and merge the variant into the existing 777 production line without disrupting manufacture of the 777 freighter.

• Initial 777-9 line acceleration expected in mid-2022
• 777F freighter production at two aircraft per month

The process has been made more challenging by the COVID-19 pandemic. While effectively decimating near-term demand for new widebodies, the effects of the pandemic have also helped stimulate an unprecedented market appetite for the 777-200LR-based freighter—a record number of which are now rolling down the assembly line.

The uptick in freighter demand, which has seen production grow to around two aircraft per month, has provided a lifeline to the company as it strives to level production amid the turmoil of market uncertainty, the 737 MAX’s return to service, the 777X delay and the ongoing disruption to 787 deliveries.

“We have really focused on getting this production system ready, with all new initiatives put in place and stable, before we brought the 777-9 over from our low-rate line,” says Brad Zaback, vice president and general manager of Boeing’s 777 program, who gave Aviation Week an exclusive behind-the-scenes update on current progress. As with previous new model introductions, not to mention to avoid disruption, Boeing began building the 777X by first assembling an initial batch of 777-9s on a low-rate initial production (LRIP) line located in Building 40-24 at the company’s facility in Everett, Washington. This site is adjacent to the main 777 line in Building 40-25.

In late 2020, with the expectation that certification testing would likely begin in early 2021, Boeing also began a trial of building a 777-9 on the main line. The effort was tentative because the 777-9 is not only significantly longer than the 777-300ER, but it also incorporates larger General Electric GE9X engines and an all-new composite wing with associated design and manufacturing changes to the midbody. Assembly is also complicated by the novel 11-ft.-long folding wingtip sections that are installed and checked out on the production line.

All of these changes had to be introduced onto a line that was by now moving at a much faster rate than the 777-9s produced on the LRIP line. “We also wanted to make sure that we could build the 777-9 and the 777F together, and that it wouldn’t cause disruption,” Zaback says. “Our team started getting improvements worked out more quickly than expected, and the trial was successful enough that—although we were planning on making the move later this year—we were able to shut down the LRIP in the first quarter. We’re now on our fifth non-LRIP 777-9 with a sixth about to come through.”

The move is “really paying off in terms of improvements in first-pass quality, safety and stability,” he adds.

“We measure our work by the amount that gets done the day it is assigned,” Zaback says. “So, we measure stability on the planned work that day and how much of it gets accomplished. You can work overtime or on the weekends if you get behind, but it’s not very stable. With a brand-new airplane, you’re always working to get that stability so that it flows at the same pace as the existing metal-wing aircraft [that] have been built for a long time.”

Boeing also used the transition as an opportunity to update the production system for improvements in ergonomics, health and safety. The 777 wing, for example, was traditionally joined to the fuselage and completed using a canted support structure that provided a platform for line mechanics. Now, much of the process is automated using a large, arch-shaped portable tooling device that is lowered onto the wing-body join. “Everybody would have to work kind of sideways all day, but now this has really changed the dynamics by not having any of that structure here,” Zaback says.

The company has also taken the concept of kitting—or providing parts to line workers—for production efficiency to the next level as part of the 777X transition. “We’ve kitted parts in the past, but they weren’t a full kit,” Zaback says. “So now everything, including all your tools you need for that job, is included.”

The updated kitting plan applies equally to the heritage 777 models as well as the new 777-8, he says, but “it’s really about enabling the 777-9 for the long term and the family of airplanes that will come with it because at some point in time the metal-wing version will be done.”

“We are still investing in the metal wing and want to keep building that because we’re selling a lot of them right now, but the overall effort is really focused on the 777-9,” Zaback adds. Although the 777-300ER is still offered by Boeing, the stalwart passenger version—which proved to be a popular successor to the 747-400—appears to have run its course. The last -300ER, destined for Russian airline Aeroflot, was quietly rolled out in April and delivered without fanfare on Sept. 30.

For the freighter, however, the picture is reversed.

“Because the demand has been so great, we’ve actually added a lot of additional production positions over the last six months,” Zaback says. “We did that in conjunction with the supply base to make sure that they can handle it, and we’re stable now at around two a month.”

Boeing has seen a steady increase in business for the 777F, with 105 orders placed since the start of 2018. Thirty orders have been placed since the start of this year alone. Since the first 777F was handed over in 2008, Boeing has delivered 212 aircraft and has around 60 unfilled orders.

With no plans to accelerate 777F assembly just yet, the ramp-up will therefore be focused on the 777-9 production and a subsequent initial step-up in mid-2022.

“All the airlines have told us they’re going to recover in 2024, so we will start delivering at the end of 2023,” Zaback says. “By then, we will be looking at 4-5 deliveries per month starting right away in 2024. You can’t just turn that on, you’ve got to start turning it on now. So, this is our time to get stable and get ready.

“As we start that process next year, we’ll start ramping up in very deliberate small steps every nine months,” he adds. “We will keep it really stable that way.”

The program’s overarching pacing item, however, remains the path to certification. Following heavy regulatory scrutiny in the wake of the 737 MAX saga, Boeing was initially confident that its revised engineering and safety oversight structure would clear the way for 777-9 FAA type inspection authorization (TIA) approval early in 2021.

However, following calls from the European Union Aviation Safety Agency (EASA) for modifications to the flight control system and an uncommanded pitch event during flight testing, Boeing conceded certification would take longer than expected. In January 2021, the company announced a $6.5 billion program charge and the need for 12-16 months of additional development time, pushing first deliveries to the end of 2023. Further reasons for the extensive delay were revealed five months later, when a letter from the FAA listed the flight control system among 11 issues and concerns hampering progress toward TIA approval.

While not commenting on the potential timing of TIA, Zaback says the relevant work with the FAA is making progress.

“We are also making progress with the EASA piece of it,” Zaback says. “The team knows what we need to go do, and we’re just closing in on the details now. The changes to the software and hardware are baked into our plan.

“We also really had to change our design assurance processes,” he adds. “Now everyone’s trained in that process and we’re executing it. The progress in some areas is not as fast as we’d like, but that’s why we put a schedule together that had some room in it—and our customers were not going to be able to take the aircraft any sooner.”

Meanwhile, Boeing has continued flight testing using four development aircraft. “Even without getting TIA, we’re doing these Boeing flights,” Zaback says. “If you’re going to learn anything, it’ll be there. We’re continuing to get past the testing, and the airplane is maturing. As long as we’re doing that, we’re going to be in great shape.”

Any discoveries made during flight testing will result in potential changes to the final production configuration, so catching them early is vital, says Zaback. “Some of the higher-risk tests are behind us and there’s a couple more I’d like to get through because then you know that everything is stable in that part of the airplane,” he says. “For us it’s all about stability. If there’s a change, we want to incorporate that in sequence and make sure our team knows how to do that job.”

Typical key tests with the potential to affect the configuration include brake system evaluation. The first 777-9, dubbed WH001, was scheduled to conduct brake tests on Oct. 1 at Clinton-Sherman Airport in Burns Flat, Oklahoma, using the former U.S. Air Force Strategic Air Command base’s extremely long 13,500-ft. runway.

More remedial work, or change incorporation, will be required for the initial aircraft produced on the LRIP. Including the four test aircraft, around 26 777-9s are believed to have been assembled—some 20 of which on the LRIP line. Aside from the test fleet, none of the aircraft have engines or interiors and they are currently in storage at various locations around Everett’s Paine Field.

All of the aircraft in question will ultimately be fitted out and refurbished for eventual delivery.