Helicopters have clear advantages over fixed-wing aircraft. But they also have a big drawback: they are slow. The fastest struggle to exceed about 320kph (200mph)—less than the cruising speed of a second-world-war-era propeller plane. At an aircraft-testing facility in Florida, though, a strange-looking helicopter has taken to the skies that may help to close that gap http://econ.st/1FzdyET
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