The Blade That Would Make Helicopters Almost Silent

Illustration for article titled The Blade That Would Make Helicopters Almost Silent

Helicopters make a lot of noise because of a physical phenomenon called blade-vortex interaction. Eurocopter engineers have developed a new kind of rotor blade that attenuates this problem. It's called Blue Edge, and—as you can hear—it works beautifully:

The new blade shape is combined with another technology called Blue Pulse, which adds three flaps to the edge of the rotor blades. These flaps move up and down at 15 to 40 times per second, using piezoelectric motors that also help to reduce the blade-vortex interaction. [Autopia]



The blade only reduces sound by 3-4 Db... on a logarithmic scale, sure, it is significant. But compared to the magnitude of the vibrations that these blades endure, I asked a good friend of mine who is an engineer in rotor design at Sikorsky. He put it like this: "calling it silent is like calling a hummer efficient."

Furthermore, he estimates that materials on some of the larger blades would cost hundreds of thousands themselves. So I would imagine that the tech and maintenance behind this blade is astronomical. Best of luck to Eurocopter's marketing campaign.