Lighter By Design
The 777 makes extensive use of lightweight, cost-effective structural materials that lessen the overall weight of the airplane and contribute to the fuel efficiency of the 777. For example, an improved aluminum alloy is used in the upper wing skin and stringers. Known as 7055, this alloy offers greater compression strength than previous alloys, enabling designers to save weight and also improve corrosion and fatigue resistance.
Progress in the development and fabrication of weight-saving advanced composite materials is evident in the 777. Carbon fibers embedded in recently available toughened resins are found in the vertical and horizontal tails. The floor beams of the passenger cabin also are made of these advanced composite materials.
Other composite applications include those on secondary structures such as aerodynamic fairings. Composites, including resins and adhesives, account for twelve percent of the 777's structural weight. This is the same type of composite material used on the 787 Dreamliner.