Air Force X-Plane Seeks to Solve Flutter Problems
An experimental drone will fly for the first time this summer to kick off an investigation into technologies that could lead to light, flexible aircraft that can actively suppress the dangerous phenomena of flutter.
The Air Force Research Laboratory will use the multi-use technology test bed, designated X-56A, to explore issues related to uncontrollable vibrations caused by airflow over the wings.
Flutter once famously caused an F-117 stealth jet to bust apart during an air show in 1997.
Engineers hope to fix the flutter problem by adjusting software programs in the experimental aircraft’s flight control computer.
Built by Lockheed Martin Corp., the test drone measures 7.5 feet long with a 28-foot wingspan. It weighs 480 pounds and features a pair of 52-pound thrust turbine engines. The long, thin wings make it susceptible to furious vibrations. But the X-56A is designed for easy wing replacement so that a range of flexible options can be tried. In addition, officials plan to add another hard point to mount a third engine or structural support for examining joined wing configurations. This will allow for the testing of a wide range of advanced aerodynamic concepts, Air Force officials said.
The Air Force tests are expected to wrap up in the fall, after which NASA’s Dryden Flight Research Center will take control of the test aircraft for further experiments.
The X-56A is a low-speed research aircraft, but it has the potential to inform designs for future supersonic planes, NASA officials said. They cited the X-54, a proposed supersonic aircraft that seeks to muffle sonic boom and allay concerns about noise, which could open the door for supersonic commercial flights over the United States.