Ever since the Boeing Co. launched its new 787 Dreamliner, it has plugged the plane's fuel efficiency. Some of the 787's fuel savings comes from its reliance on lightweight carbon fiber composite materials.
But a portion of the Dreamliner's efficiency stems from the way the plane uses power.
"A very large portion of the 787's (fuel) efficiency comes from its engines," said Boeing's Mike Sinnett, the 787's chief systems engineer.
Sinnett recently gave the media a glimpse of how the Dreamliner's major systems work at the company's lab in Seattle, where Boeing employees simulate flying the 787.
Boeing left it to manufacturers General Electric and Rolls Royce to design the 787's engines in a way that consumes less fuel and produces fewer emissions. The planemaker created its 787 to be able to swap engines from either manufacturer without major changes to the jet, a change from previous plane programs.
It's not just the engines that reduce the amount of fuel burned on a 787. It's also the way the engines will be operated and how the rest of the plane will use power. Conventional aircraft rely heavily on the engines to power systems such as in-flight entertainment, de-icing mechanisms and lighting. The Dreamliner draws about 35 percent less power from the plane's engines than do similar-size aircraft on the market.
For the first time, a Boeing jet will rely on electrical, rather than hydraulic, power to keep ice from building on the jet's wings. Normally, hot air from the plane's engines is funneled to the wings as part of an aircraft's de-icing system. Bleeding hot air from the engine to run functions such as de -icing tends to waste a lot of energy, Sinnett said.
"Generating only the power that you need when you need it is generally a good thing," Sinnett said.
That's why the 787 will run many of those operations off power from high-voltage generators. The Dreamliner will distribute power at a higher voltage - roughly twice as high - as most planes on the market today. The 787 can generate almost 1.5 megawatts of electrical power.
In reducing the plane's dependence on hydraulic power, Boeing also reduced some of the heavy equipment jetliners typically carry on board to support the traditional power system - a difference of thousands of pounds, Sinnett said.
Some of the weight loss comes from making electrical systems, such as those used for flight control, smaller than ones used on previous planes, such as Boeing's 777. But it's the effectiveness of the 777's electrical power that gives Boeing confidence its increased reliance on electrical power will work.
The 777 recently completed its 1 millionth flight under the government's extended operations regulations, and hasn't suffered a major electrical failure yet.
Boeing continues to test its new 787's systems at the Seattle lab, where the guts of the Dreamliner began coming together about five years ago, said the company's Kamiar Karimi. In the lab, Boeing can test how the Dreamliner would respond to a variety of problems, such as engine failure.
"We are continuing testing," Karimi said. "We are continuing learning."
Reporter Michelle Dunlop: 425-339-3454 or mdunlop@ heraldnet.com.
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