NASA Tests Folding-Wing Tech

A new technology that enables aircraft to fold their wings to different angles while in flight was successful in recent flight tests, NASA has reported. The tests took place at NASA's Armstrong Flight Research Center in California, as part of the Spanwise Adaptive Wing project. Folding wings have been tried in the past, NASA said, notably with the North American XB-70 Valkyrie in the 1960s. However, the ability to bend wings in flight was dependent on heavy and bulky motors and hydraulics. The new technology uses a cutting-edge, lightweight shape-memory alloy that moves in response to heat, activating a twisting motion that moves the wing's outer portion up or down by up to 70 degrees. The new technology weighs up to 80 percent less than the traditional system. It can be used in either subsonic or supersonic flight, NASA said.

"There's a lot of benefit in folding the wingtips downward to sort of ‘ride the wave' in supersonic flight, including reduced drag," said Matt Moholt, principal investigator for the project. This can make supersonic flight more efficient, he said. "We put the SAW technology through a real flight environment, and these flights not only proved that we can fly with this technology, but they validated how we went about integrating it," said Moholt. "We will use the data from these flights to continue to improve upon the actuation system, including speed and smoothness of actually folding the wings, and we'll apply them as we get ready to fly again." NASA worked with Boeing to develop the technology. More flights with the remotely piloted test aircraft are planned for this summer.