NASA¹s Preliminary Research Aerodynamic Design to Lower Drag (PRANDTL-D) No. 3 aircraft successfully flew its first flight on Oct. 28, 2015. This flight test is the first of many that are aimed at improving flight efficiency. Engineers estimate future aircraft could see more than a 30 percent increase in fuel economy. The new wing design eliminates the weight & drag of the modern aircraft tail and its flight control surfaces.