Lockheed Martin is hoping to start tests later this year of new anti-flutter technology on board its X-56A unmanned air vehicle (UAV).
The company developed the X-56A as part of an Air Force Research Laboratory programme known as the Multi-Utility Aeroelastic Demonstrator. It aims to build a UAV that can be used to test a technologies ranging from flutter suppression to gust load alleviation.
There are two X-56A air vehicles, nicknamed Fido and Buckeye, each boasting a 28ft (8.5m) wingspan and a weight of 480lb (216kg).
Lockheed Martin has flown Fido with a stiff wing eight times. These consist of 36 layers of carbonfiber, providing sufficient rigidity to minimize flutter.
But now the company is in the process of putting much lighter flexible wings on the aircraft. Made from a skin consisting of just two layers of glassfibre, the flexible wings provide a dramatic increase in efficiency. The downside is that they are far more susceptible to flutter, according to X-56A technical program manager Ed Burnett.
Lockheed Martin plans to reduce flutter in the flexible wings through the use of flight controls.
The company believes that building a more efficient UAV that minimizes flutter could have applications for high-altitude intelligence, surveillance and reconnaissance aircraft for the US military as well as very-high-speed civilian aircraft.
With the anti-flutter technology and flexible wings “I can fly higher because I weigh less, I can fly further because I weigh less, and I can fly faster because one of the limiting factors on aircraft is flutter,” says Burnett.