At NASA, science for science’s sake is being practiced like it’s 1969, and the agency’s latest project could revolutionize the way that airplanes are built. Or not. NASA’s X-56 remotely operated test vehicle (we called these models when I was a kid) looks like a Long Eze with a twist, literally. The plane’s super thin and flexible high-aspect ratio wings were designed to show that aircraft with light and structurally uncomplicated wings could be a practical way for future planes to be much and more fuel efficient. Only problem was, the planes are susceptible, says NASA, to flutter at lower airspeeds. Flutter is a killer. Once it begins, the structures that start to oscillate can break themselves apart and bring the entire aircraft down with them.
NASA’s fight against flutter isn’t new. It’s been working on active-wing solutions since the 1970s. But today, by being able to throw bigger computers and an advanced understand of flutter modes at the problem, they hope to make progress with designing active control systems.
The latest X-56A, nicknamed “MUTT,” for Multi-Utility Technology Test Bed, is putting that theory to the test, with engineers using active flutter suppression and gust load alleviation. Essentially, when the wing starts to experience deviations in loads, the computer senses it and adjusts the control surfaces to alleviate the loads. And as a control, NASA has created a second set of conventionally stiff and heavy wings, that will go through the same flight envelope, to see how differently the two different structures behave at the extreme edges of the flutter envelope.
The hoped-for effect is for pilots and passengers feel as though they’re flying in an airplane with traditional, heavy structure wings and not one with flexible, lightweight ones. NASA compares flutter to a particularly nasty dragon inhabiting a small corner of the sky. “The work we’re doing with the X-56A may not kill flutter completely,” said the project’s manager Ed Burnett, “but we will have a much better idea of how to tame it.”
Learn more at NASA.