Friday 17 November 2006

Fly Silent, Fly Cheap

Stolen from wired ... Not that interesting but I like the name.
Dave Demerjian 2006-11-15 02:00:00.0 Researchers have unveiled design plans for a passenger plane they claim will be no louder than a washing machine and will use 25 percent less fuel than current jetliners. Some environmentalists and aviation enthusiasts are hailing the futuristic jet as the most important commercial aviation development in the last half century, but don't book your tickets yet -- it could be decades before this plane takes flight. Dubbed the SAX-40, the new plane was developed by a consortium of scientists, academics and aviation companies that include Boeing, UPS and BAA, the company that runs Britain's airports. The project was led by the Cambridge-MIT Institute , or CMI, a joint venture between the two universities funded by the British government. Unlike the tube-shaped fuselage found in today's passenger jets, the SAX-40 features a radically different wedge-shaped airframe that acts as a single flying wing, creating extra lift. Its engines are mounted on top of the aircraft rather than under the wings, and are made with variable jet nozzles, which allows for slower propulsion during takeoff and climb. The plane is smooth and streamlined, with a drooped leading edge, a simplified undercarriage, and no slats or flaps. While the SAX-40's increased fuel efficiency will appeal to airlines coping with record high jet-fuel prices, creating a quieter plane was always the design team's primary goal. The new engine design will lower cabin noise to a soothing hum; more importantly, the plane won't rattle the windows of houses parked under approach and takeoff paths. "We wanted an aircraft that would be imperceptible to the human ear (from the ground) during takeoff and landing," says Dr. Zoltan S. Spakovszky, an MIT professor and one of the chief engineers on the 7-year project. "Fuel efficiency is important, but we chose to make noise our primary variable." Les Blomberg, director of the anti-noise advocacy group the Noise Pollution Clearinghouse , says the SAX-40 design is significantly quieter than the current generation of jets. "Putting engines on top allows the body of the plane to act as a noise shield," he explains. "And eliminating flaps will also significantly cut down on noise." But he cautions that the SAX-40's "silent aircraft" label should be taken with a grain of salt. "It's not really going to be silent," he says. "Much quieter, absolutely. But not silent." Blomberg says there is a strong economic incentive for the aviation industry to focus on noise. "Many U.S. airports are near capacity, but there's very well-organized community opposition to expansion," he says, citing Teterboro Airport in Northern New Jersey and Hanscom Field in the Boston suburbs as two examples. "Airports and airlines aren't going to be able to grow unless they find a way to respect the surrounding communities." In the hype surrounding the release of the SAX-40 design, it's easy to overlook the enormous technological and market challenges that would need to be addressed before the project becomes a reality. "Research studies like the SAX-40 project are great for spurring new ideas and fostering innovation," says Bill Glover, Director of Environmental Performance Strategy at Boeing. "They're important, but they're very different from product development studies, which must also consider passenger needs, market forces, safety, regulations and a host of other variables." Boeing has used concerns about noise and fuel efficiency to market its new 787 Dreamliner , which will enter service in 2008 and features a lighter airframe; smaller, quieter engines; and laminar flow control to reduce drag. With SAX-40s' developers predicting it will take at least 25 years before their design becomes a reality, planes like the 787 may be the closest today's generation of travelers ever comes to quieter flight. "It's not likely to happen in my lifetime," says Blomberg of the SAX-40. "By the time this plane becomes a reality, most of us will be deaf or dead."

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