Piasecki X-49 "SpeedHawk"

The Piasecki X-49 "SpeedHawk" is an American four-bladed, twin-engined experimental high-speed compound helicopter developed by Piasecki Aircraft. The X-49A is based on the airframe of a Sikorsky YSH-60F Seahawk, but utilizes Piasecki's proprietary vectored thrust ducted propeller (VTDP) design and includes the addition of lifting wings. The concept of the experimental program was to apply the VTDP technology to a production military helicopter to determine any benefit gained through increases in performance or useful load.

"SpeedHawk" is a concept aircraft[1] based on applying X-49A compounding concepts to a production UH-60 Black Hawk offering better performance, range, and increases in useful load. The "SpeedHawk" aircraft includes an SPU (third engine), high forward-swept wing concept, a 45-inch "fuselage plug" cabin extension, and several other drag reducing and performance-oriented improvements, including a rotor hub fairing, landing gear streamlining, and a fly-by-wire flight control system.he X-49A made its first flight on June 29, 2007 for 15 minutes at Boeing's New Castle County (KILG) flight test center.[10] This flight included hovering, pedal turns, and slow forward and sideways flight using the VTDP for anti-torque, directional and trim control. The X-49A project has been silent since completing its initial testing phase in 2008, with over 80 flight events with and more than 80 total hours logged.