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Frontiers October 2012 Issue

showcases just how much more is possible. In September, Boeing test pilots flew ecoDemonstrator from Seattle to Glasgow, Mont., for about three weeks of extensive testing. One of the pilots participating in the testing is Carriker, now chief pilot for New Airplane Development, Boeing Test & Evaluation. Glasgow, in the northeastern corner of Montana, is the perfect place to measure how much noise a jetliner makes—it’s pretty much in the middle of nowhere. During World War II, the airfield was used to train B-17 pilots, and in late 1944 a camp was built there to house German prisoners of war. In the 1960s, a B-52 strategic bomber wing was located at what by then was Glasgow Air Force Base. The base closed in the 1970s and much of the property was purchased by Boeing as an aircraft test facility. Today, the site is maintained by Montana Aviation Research Co., a Boeing subsidiary. Billings and Great Falls, the two nearest cities with commercial airline passenger flights, are hundreds of miles away. The remoteness of the site, the lack of background noise, no air traffic and a massive 13,500-foot (4,100-meter) runway make it ideal for flight testing. It’s essentially a supersensitive listening post—for all kinds of noise made by an airplane. Scattered about the site and under the flight path taken by Boeing test aircraft is a phased array of microphones. They work like an acoustic camera and can pinpoint specific aircraft sounds, even the noise made by turbulence from the movement of control surfaces on the wing during landing. Nearly 2,000 different listening devices were deployed for the ecoDemonstrator testing at Glasgow to measure both airframe and community noise. “We can actually tell which component on the plane is making the noise,” explained David Akiyama, ecoDemonstrator program manager. Noise heard on the ground is referred to as “community noise.” During takeoff operations, this mostly comes from the engines. But on landing, both engine noise and airframe noise, such as that made by turbulence from the wing flaps and the landing gear, contribute to community noise. Among the technologies on the ecoDemonstrator tested at Glasgow is an “adaptive trailing edge,” which improves airflow at the trailing edge of the wing. This smart wing technology allows the wing aerodynamics to be optimized for each phase of flight— takeoff, cruise and landing. On takeoff, for example, the airplane climbs faster, which means less community noise because the airplane spends less time close to the ground. During cruise, the trailing edge adjusts to reduce airplane drag to lower fuel burn and reduce carbon dioxide emissions. Akiyama referred to this innovation as “wing morphing.” Think of a bird in flight, he said. A bird will change the shape of its wings depending on whether it’s climbing, gliding, diving or landing. “So we change the shape of an airplane wing for various flight conditions,” he said. Another important technology on ecoDemonstrator tested at Glasgow is a “variable area fan nozzle,” which opens the engine 22 BOEING FRONTIERS / OCTOBER 2012


Frontiers October 2012 Issue
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