Most helicopters are built for hovering, not for speed. But the Eurocopter X3 is built for both. The demonstrator tilt-rotor aircraft proved as much when it set a pair of air speed records earlier this month.
Based on the Eurocopter EC155, the X3 is a hybrid helicopter. That is, in addition to its five blade main and tail rotors, the X3 is also outfitted with a pair of stubby wings (similar to those aboard the Mi-24 HIND but with propellers instead of missile pods) that provide up to 80 percent of the aircraft's lift. A pair of 2270 HP Rolls-Royce Turbomeca RTM322 turboshaft engines drive all four rotors and allow for a 12,500 foot service ceiling and blindingly fast speed.