Use of carbon composites in the Dreamliner 787 was a huge breakthrough in aircraft design and materials technology.
In the Boeing 777X, Boeing is taking the technology to a higher level.
Start with design. Boeing engineers are taking advantage of the ability to curve composites to improve aerodynamics. Boeing VP Eric Lindblad says: “If you watch eagles fly, their wings are very curved up in the air. This is the most optimum shape to achieve aerodynamic lift.” The 777X incorporates a curving shape. That combines with the inherent flexibility of carbon composites compared to traditional aluminum wings.
The wings are also longer than tradtional wings—about 20 per cent longer, making the plane almost glider like. Twelve-feet wing tips will fold so that current ground equipment can be used.
Manufacturing has also advanced. Carbon fiber lay-up will be done by giant robots that function like 3-D printers in the sense that layers are sequentially added.
The 114-feet long and 23-feet wide composite wings will be produced with Electroimpact gantry-style automated fiber placement machines designed specifically for large aerospace parts. Spars will also be made in the plant as a single piece, another significant advance. The machine can lay down a full lengthwise layer along the spar in approximately 10 minutes.
Lay-up takes place in the cleanroom of a newly opened manufacturing plant in Everett, Washington. The other half of the plant houses giant, newly designed autoclaves for bonding the tape layers and an area for trimming and drilling the cured wings.
The fact that the parts will be manufactured by Boeing in Washington is also an interesting development. Boeing had spread the enormous financial risk of the Dreamliner by using a global supply chain to manufacture components. An assembly plant was built in South Carolina to take advantage of lower labor costs and tax breaks. Boeing selected the Everett site as a part of a deal (and eight-year contract extension) with the International Association of Machinists & Aerospace Workers (IAM) District 751. As part of the contract extension, the company agreed to fabricate the parts for, and assemble, the 777X composite wings in the Puget Sound region.
Boeing says that the 777X will be the largest and most efficient twin-engine jet in the world, with 12 percent lower fuel consumption and 10 percent lower operating costs than competitive planes.
The 777X program has received commitments for 320 airplanes from six customers worldwide. Production is set to begin next year.