Sikorsky Aircraft vice president of research and engineering Mark Miller confirmed that the Stratford, Conn.-based helicopter manufacturer plans to develop a civilian version of the S-97 Raider, which is a contender for the U.S. Army’s armed aerial scout program. The S-97, he said, is a production-ready, “scaled-up version of the X2 demonstrator,” with both helicopters having contrarotating rotor blades and a pusher propeller that enables high-speed forward flight. A civil variant of the S-97 would be “ideal” for offshore oil, search and rescue and VIP transport, according to Miller.
Both the Sikorsky X2 and the Eurocopter X3 have propellers and both are targeting higher cruise speeds; however, their respective designers have not been working to the same principles.
The X2 is effectively a semi-compound helicopter, having contra-rotating main rotors and one aft propeller, while the X3 is a true compound with a single main rotor, wing stubs and two side-mounted propellers.
Sikorsky Aircraft’s X2 technology demonstrator achieved a forward speed of 181 knots on a test flight today at the Sikorsky Development Flight Center in West Palm Beach, Fla. The contra-rotating coaxial rotor prototype is designed to demonstrate that a helicopter can cruise at up to 250 knots while retaining excellent low-speed handling and efficient hovering characteristics, as well as a seamless and simple transition to high speed.