NASA is currently testing some new technology that could benefit the aerodynamics of both subsonic and supersonic aircraft. The effort has been dubbed the Spanwise Adaptive Wing project (SAW). According to the agency, the folding of the wingtips during flight would give aircraft aerodynamic benefits such as reduce drag and weight. The agency admits that the idea of folding wingtips isn’t new but other applications were generally used to save space during storage. The difference here is, these tests are being conducted to find ways folding tips could benefit the aircraft during flight.
NASA conducts a flight test series to investigate the ability of an innovative technology to fold the outer portions of wings in flight as part of SAW project. Flight tests took place at NASA’s Armstrong Flight Research Center in California, using a subscale UAV called Prototype Technology-Evaluation Research Aircraft, or PTERA, provided by Area-I.
NASA Glenn Research Center in Cleveland developed the alloy material and worked with Boeing Research & Technology to integrate the material into an actuator. The alloy is triggered by temperature to move the outer portions of wings up or down in flight.
The ability to fold wings to the ideal position of various flight conditions may produce several aerodynamic benefits for both subsonic and supersonic aircraft.
“In supersonic flight, yaw stability becomes a big issue,” said Moholt. “If you’re flying supersonically, you have tons of lift. Let’s say you need more yaw control. Well, if I fold the wing portion all the way down, I may be able to trade lift in favor of more yaw control where I need it and less lift where I don’t need it.”
It’s a very interesting project and if any redeeming value comes of it, you can be certain we’ll see it at some point.