The Sikorsky X2 helicopter is alaredy broken the speed record of 249 mph for rotorcraft in 1986, achieving a maximum speed of at 258 mph one-hour. The Sikorsky X2 has double-decker, quadruple blade, with a six-bladed prop in the back, and it's all designed to cruise at high speeds. The Sikorsky X2 Helicopter is an experimental aircraft designed to "demonstrate that a helicopter can cruise comfortably at 250 knots while retaining such desirable attributes as excellent low-speed handling, efficient hovering, and a seamless and simple transition to high speed. "
