NASA’s Armstrong Flight Research Center engineers are working on an increasingly complex aircraft called the Preliminary Research Aerodynamic Design to Lower Drag, or Prandtl-D. Resembling a boomerang, the aircraft features a new method for determining the shape of the wing with a twist that could lead to an 11-percent reduction in fuel consumption. In this photograph, the Prandtl-D No. 2, which had a 12.5-foot wingspan, lands following a flight test.
On Oct. 28, 2015, the 25-foot remotely piloted Prandtl-D No. 3, which has a 25-foot wingspan, gracefully glided following a bungee-like launch during a one minute, 33 second flight. Continued success of the Prandtl-D aircraft could validate future aircraft designs using the same wing loading, resulting in an 11-percent fuel savings. Another 30 percent fuel savings could be achieved if future designers use the controls benefits of this new wing design to eliminate the use of aircraft tails, thus flying more like birds.