Eurocopter announced the week of February 25 new "Blue Edge" and "Blue Pulse" technology that significantly reduces the noise generated by a helicopter blade. Tested on an EC155 helicopter, the Blue Edge blade itself created a three to four decibel drop in noise and then Eurocopter added more technology. For the blade, itself, Eurocopter dramatically redesigned the shape, creating what might best be described as a seagull-wing shaped bend at the blade's tip. It then layered active "Blue Pulse" technology on top of the Blue Edge design. Blue Pulse adjusts three trailing edge flap modules 15 to 40 times per second via piezoelectric motors. The flaps move to reduce the effect of blade/vortex interaction. That interaction occurs as a trailing blade encounters the vortex of the preceding blade, causing an audible "slap." And adjusting the interaction dramatically reduces the slap. For disbelievers, the company has supplied audio. Find it after the jump.
Eurocopter plans to incorporate the two technologies into its "Bluecopter" and says the goal is to create a more neighbor-friendly helicopter that produces less noise with reduced emissions. Click here for an audio comparison of Bluecopter to non-Bluecopter technology in action.