Big jets get a lot of bad press, but what about helicopters? Sure, they're used to fight forest fires and conduct dramatic rescues at sea. And yes, they can take off and land vertically, making them ideal for city centers or hospital helipads. But helicopters are noisy and not all that fuel efficient. And compared to planes, they're also quite slow.
Sikorsky, a company owned by United Technologies, is working to change that. They're developing a copter that would cruise at over 275 miles per hour, which is more than 50% faster than most current models. They're doing it with a technology that they call X2, which the company is hyperbolically toting as a "game changer" in the helicopter industry.
At the heart of X2 is a coaxial rotor system. Most helicopters have rotating airfoil shaped blades on top of the fuselage. When these blades turn, air flows more quickly over the tops than it does below, creating lift for flight. This lift moves copters vertically off the ground, but also causes the fuselage to spin in the opposite direction, which is known as the torque effect. A set of smaller, rear-mounted perpendicular blades counteracts this effect and keeps copters flying straight.
X2 technology is different because it uses a coaxial rotor system with blades attached to two separate hubs. These hubs move blades in two different directions, eliminating the torque effect. Which means the rear blades can be used as a propulsion system, boosting the helicopter's speed.
Sikorsky recently unveiled an X2 "technology demonstrator" at the 2008 Heli-Expo. They'll use this test craft to continue developing the X2 technology in preparation for a first flight, date TBD.
Image: Sikorsky
