Boeing 787 Dreamliner - Mark Wagner [32]
One of the most dramatic features of the finalized aircraft, however, was the unusually high upswept wing angle, or dihedral. “You are seeing this is what happens when you build a composite wing,” said Bair. The slender 197-foot wingspan of the baseline 787-8 had an aspect ratio of 10, compared with 8.68 on the 777-200. But despite the narrower chord of the wingbox, and of the wing itself, the overall stiffness would be the same as for a conventional aluminum structure.
It was also revealed that the engine nacelles would feature noise-reduction chevrons as standard features. These “cookie cutter”–like shapes had already begun to be introduced on production engines such as the GE CF34 regional jet engine and had been the subject of careful noise monitoring tests among Boeing, Rolls, and GE as part of the 777-based Quiet Technology Demonstrator project.
Behind the scenes, the 7E7 went on a diet to lose weight. The weight-saving campaign, broadcast on banners throughout the Everett design offices to press home the message to employees, had been launched in December 2004 and by mid-January 2005 had started to produce results. Alarm bells had rung when the manufacturer’s weight crept above 3 percent over target, but “was trending downward” below 2.5 percent within a few weeks of intense effort, said 7E7 chief project engineer Tom Cogan.
Graphic: Gareth Burgess
Maintenance cost advantages were designed as basic into the 7E7. Boeing’s aim was a 30 percent saving in airframe maintenance costs per year by the time of the first scheduled heavy structural inspection, or “D-check.” In the 7E7 this was planned for twelve years, rather than eight for the 777 and six for the 767. The advantage was expected to grow with age, and be about 60 percent by the twenty-fourth year. Line and base maintenance check intervals were similarly extended to a thousand hours and thirty-six months, respectively, compared to five hundred hours and sixteen months for the 767 and six hundred hours and twenty-four months for the 777. Here an ANA Boeing 767 undergoes a D-check at Tokyo Haneda. Mark Wagner
Digital definition played a key role in the swift rate of progress compared with previous programs. A series of Cray supercomputers racked up more than 650,000 hours of processing time on the design, more than for any other commercial jetliner, and differentiating the 7E7 from even the 777, which had pioneered digital design processes at Boeing. Unlike the 777, where digital design data had been converted into conventional drawings to be released to manufacturing, the 7E7 would remain digital throughout. “This aircraft is being digitally defined, and we will go straight from digital definition right to building the aircraft,” said Cogan.
Dassault Systèmes’ virtual design (CATIA) toolset, used on the 777 to great success, was updated for use on the 787. However, with CATIA the digital door had barely cracked open. Boeing saw endless possibilities for using an integrated digital data system to not only design the aircraft and check everything fitted together in a virtual 3-D world, but also for planning the tools that made the parts, the manufacture of the parts, and even product support. It was a radical approach that, in many ways, was the only way to achieve Boeing’s massively ambitious 787 undertaking and the shift