SUPER FAST X 49 A Helicopter for US military

An interesting helicopter for the US air force navy and army The Piasecki X49 SpeedHawk is a fourbladed, twinengined, experimental compound helicopter under development by Piasecki Aircraft. The X49A is based on the airframe of a Sikorsky YSH60F Seahawk, but utilizes Piasecki s proprietary vectored thrust ducted propeller (VTDP) design and includes the addition of lifting wings.