Eurocopter X3: The world's fastest copter
(PhysOrg.com) -- If you asked a child how they would make a helicopter go faster, they would probably tell you to add another engine. The answer would be Zen simple and dead right. The engineers at Eurocopter also seem to have that same mentality and it worked.
"The X3’s speed milestone was reached on May 12 during stable, level flight – with the hybrid demonstrator maintaining a true airspeed of 232 kts. (430 km./hr.) for several minutes. This occurred during only the third mission after a scheduled upgrade that integrated the X3’s definitive gearboxes, enabling it to operate at full power." (font: eurocopter.com)