Must Helicopters Be So Noisy?
The answer depends on what you mean by 'must.'

By Fred George
February 2006

It was a typical Chamber of Commerce late fall day on the beach at Puamana, just south of Lahaina, Maui, with brilliant sunshine, soft tradewinds, billowy cumulus clouds and 80 F temperatures. The only sounds to be heard were the breakers washing up against the rocks along with some mynahs singing in the acacia trees. I strolled down to the shore and settled into a beach chair to peruse A Hawaiian Reader; occasionally catching a brief glimpse of a sea turtle just beyond the shore break or glancing at the fishing boats plodding along off the coast.

A lull in the surf and a pause in bird songs allowed me to become aware of another soft sound, this one coming from directly overhead. It was barely audible to me or other beachgoers. I looked up and saw a dark blue Eurocopter EC130 cruising 1500 feet above Puamana on a sightseeing mission, its pilot confident that he was not annoying, let alone provoking, the wrath of the earthbound multitudes enjoying West Maui. This helicopter indeed was one of the quietest rotorcraft I've yet seen or heard.

What a contrast to other types of helicopter operations. City residents are subjected to a sometimes all-hours clatter of public service, law enforcement, EMS and ENG helicopters. Helicopter cacophony has become a part of the urban environment, and it's no more welcome than litter or graffiti.

Why do most helicopters make so much noise? It's a question whose answer is of real and immediate concern to many people in the helicopter community. That's because helicopter noise isn't just annoying to by standers, it also motivates perturbed citizens to call city hall and demand action to quiet their neighborhoods. Increasingly, helicopter noise is becoming a practical liability for the folks who fly them because of restrictions local government officials place on their operation.

"It's no secret. It's one of the biggest priorities we have. It needs to be addressed aggressively because noise affects peripheral issues such as retention of infrastructure. The perception is that if you take away heliports, you eliminate the noise," explained Matt Zuccaro, president of the Helicopter Association International. Without nearby heliports or helipads, helicopters go away along with their noise problems. That may be the HAI's position, but there are lots of stakeholders weighing in on this issue, plus several groups within the helicopter community that view the need for noise reduction differently.

David Chevalier, president of Blue Hawaiian Helicopters based at Kahului, Maui , pushed for quiet technology for more than a decade, as former chairman of the HAI's Helicopter Tour Operators Committee. "We resolved that the biggest issue facing our industry was noise, especially where you have a lot of helicopter operations in a particular area," he said. The solution would take a breakthrough in helicopter design technology.

"We approached a number of aircraft manufacturers, telling them we needed much quieter helicopter. When we went to see American Eurocopter, they said they would create a new model to suit our needs. We wanted an aircraft that was as quiet as an EC120, but capable of carrying seven passengers, with good visibility. They asked us how much we were willing to pay and we said no more than 20 percent above the cost of an AStar."

The result was the EC130, a 5,291-pound derivative of the AS350 AStar/Ecureuil family that uses the same 847-shp, FADEC-equipped Turbomeca Arriel 2B or 2B1 turboshaft engine and main-rotor system as the Ecureuil AS350B3, an EC120 fuselage and main cabin, plus an EC135-design fenestron (ducted tail rotor) anti-torque system. The newer generation fenestron systems, fitted with an asymmetric distribution of rotor and stator blades, are far quieter than the fenestrons fitted to the AS365 Twin Dauphin. Just as importantly, the EC130 features a two-speed rotor rpm in cruise to slash outside noise levels. The result is the quietest helicopter available to the tour industry, one that is 7.0 dB to 8.5 dB quieter than ICAO Annex 16 Chapter 8 and FAR Part 36 Appendix H limits. The EC130 also handily beats the newer 1993 ICAO and 2004 Part 36 overflight noise standards for helicopters with MTOWs of 7,000 pounds or less.

 For more information please visit www.aviationnow.com/BCA