B777-9 snart klar for testing - AW&ST

‘Power On’ Marks Key Milestone For First 777-9 On Path To First Flight Guy Norris Boeing has turned on the electrically powered systems in the prototype 777-9 for the first time at its Everett, Washington, facility, setting the clock ticking toward flight tests of the initial variant of the company’s new long-range 777X flagship starting in early 2019. The “power on” milestone, staged over successive days at the end of November, comes less than two weeks after the first flight aircraft completed final body join and marks a critical test for the production and systems development changes invoked for the 777X program. The huge new airliner, which is the longest in the world at 252 ft. overall, is based on a stretch of the 777-300ER but is assembled in a completely different way than its forebear and is integrated with an all-new composite wing, new engines and systems. Parts for remaining three 777-9 flight test aircraft and fatigue airframe in production First wing spar for first 777-9 for delivery to Emirates will load in December Assembly underway on temporary low-rate initial production line at Everett The setting for this industrial sea change is Boeing’s cavernous 40-24 assembly building, where the company has established a temporary 777X low-rate initial-production (LRIP) line to avoid disrupting the adjacent 777-300ER/200F main assembly line in building 40-25. However, thanks mostly to meticulous preparations, simulations and leveraging advances made for the 737 MAX, as well as a host of lessons learned from the early days of 787 and 747-8 production, this current chapter of the 777-9 development story has so far been relatively drama-free. “We did the static-test airframe first and verified all the tools and capability, and it went very well. There were no major discoveries or hiccups. With the flight-test aircraft the wing-body join went just as well and was very clean from the structures standpoint,” says Jason Clark, vice president of 777/777X operations. “Now when you start getting an aircraft close to power on and bringing it to life, that is where the magic is,” he adds.

The 777-9’s folding wingtips, 787-based swept wing design and extended fuselage are evident in this view of the newly completed first flight-test aircraft, WH001. Credit: Boeing

“When we did the first join on the static-test aircraft in September, we gave ourselves 20 days to build it and did it in 16. With this one, they improved on that by 20% because they have already built it in the lab [digital mockup] virtually about 50 times. During the simulations, they put variability in it, changed things and really put a wrench in the works,” says Clark. “We exercised the tools and teams over the past two years and changed the design so it could be built better.” Not everything was perfect, and lessons are being learned for the next airframes to follow. “We found out what worked and didn’t work,” says Clark. “For example, as we did the wing-body join, which was one of the major issues on the 787, we used the same basic configuration as the 787 but made some significant design changes for producibility.” Most of this worked, but the production crew did encounter a single “tag” (or defect) on both the static and first flight-test aircraft. The tag was in the same location on both. But overall, the result is good news for the company’s revised production plan. “In new models. you’d normally expect hundreds of tags,” he says.

Source: Boeing

Five 777-9 airframes, four for flight testing and one for fatigue tests, are in various stages of assembly. “All four flight-test aircraft are in the LRIP, and the left wing, the final for the fourth test aircraft, has just been loaded in laydown. So that part of the system is really starting to crank. The wing for the fatigue-test aircraft is in the horizontal-build line wing assembly area, and the wingbox is almost built,” says Clark. “We also have the first change incorporation airplanes [the initial production batch for delivery] starting to load into the system, and if you go one step further, to early December, we will load the spar for the first of model that we will deliver,” says Clark. “So when people ask how the production system is going, every single position in the factory is now fully loaded.” Boeing, which completed assembly of the static-test airframe in September, is widely expected to build up to 30 follow-on 777-8/9s on the LRIP line before 777X production is fully transitioned to building 40-25 in the early 2020s. Production of the first two 777-8s for flight test is expected to follow on the LRIP line in 2020. Rollout of the first 777-9X is due in early 2019, with the first flight widely expected in the second quarter of 2019. All four 777-9 test aircraft are scheduled to be in the flight program by late 2019, with first deliveries due to begin around May 2020. First 777-8 deliveries will start in 2022. Launched in early 2013, the 777X program has remained broadly on track, although some minor schedule slippage has occurred due to development issues with the General Electric GE9X engines and manufacturing challenges associated with detailed assembly of the initial composite wings. However, despite the rollout—now expected to occur in February instead, later this month—Boeing still expects to maintain sufficient schedule margin for an on-time delivery to launch customer Emirates in early 2020.

Standing more than 11 ft. tall in the vertical stowed position, the 777-9 folding wingtips resemble winglets. The aft fuselage of the second flight-test aircraft is under assembly in the background. Credit: Guy Norris/AW&ST

Much of this confidence comes from the first aircraft’s smooth flow through the redesigned production system. Designed to ultimately handle the assembly of all 777 derivatives, including the longer-term manufacture of both metal-winged freighters and composite-winged 777-8s and -9s, the new-look production system was devised in concert with the aircraft’s design. “It’s the benefit of bringing in the build team really early. Typically, they would be brought in at [program decision point] Gate 7 [at] firm configuration. But by then it’s too late to change the design for the production system,” says Clark. “Instead, we brought folks in at Gate 3 [preliminary design refinement], and that allowed us to define and codevelop the requirements for production and test all of them while we were doing layouts and design. The result is the airplane fits together much better, and it is clean [requiring little or no rework] because you don’t have that much discovery going on.” With a common main production line the eventual goal, improvements and changes are flowing from the 777 to the 777X and vice versa. The robotic fuselage automated upright-build process introduced on the current production model is now standard for all 777 derivatives, while the dominant use of overhead cranes and large, permanent tooling fixtures or “monuments” from areas such as the wing installation have been replaced by computer-controlled automated guided vehicles that are used to position wings and fuselage sections for wing-to-body join.

Major subassemblies of the first Boeing 777-9 came together smoothly at the company’s Everett, Washington, facility, where final body join was accomplished in mid-November. Credit: Boeing

For the 777X models, the legacy monument tooling used to build wings in a vertical position has been replaced by a horizontal-build line, based on successful implementation of a similar system on the 737 program. Although this assembly process is not adaptable to the metal-winged 777 variants, all wings will be completed and readied for installation in a similar laydown “service-ready” process. “Before it would be done in the wing-body join position, where you would start stuffing the wing [with systems] on the big tools,” says Clark. “The problem is the mechanics didn’t always have good access to build it. So this way we give them much better access, and all the systems, control surfaces, wingtip and strut are all now loaded in without major monument tools. It is more like an automotive process as we shift toward part-to-part indexing.” Perhaps most important, the monument-free line will give the main line greater flexibility to account for the significant differences in size, sweep and dihedral between the 777 and 777X wings. Based on a scaled-up 787 wing, the 777X design is longer, less swept and has greater dihedral with a high degree of “gulling” on board. It also incorporates a folding tip section which, despite extending almost 12 ft. in length, resembles a winglet when in the stowed (up) position because of the aircraft’s overall large size. Although the first functional check of the folding wingtip will take place on the completed aircraft for the first few 777-9s, Boeing’s plan is to move this work further upstream to the service-ready wing station. “By airplane seven, which will be in the February/March time frame, we should be able to do the functional check—up/down, up/down—at that station,” says Clark. “Even though at final assembly we will still do a ship’s power functional test from the flight deck, this one will allow us to not have to do that in the future. Once we prove that out, then it just becomes a simple confirmation and allows us to rebalance our production.”