Eurocopter is at the forefront of reducing noise emission of helicopters. Its entire new generation of helicopters – the EC120, EC130, EC135, EC145, EC155 as well their heaviest complement, the EC225, have noise levels well below ICAO limits. The EC120, EC130 and EC135 even comply with the most restrictive levels in the world, the Grand Canyon National Park Standard.
Rather than remaining an abstract calculation with technical values, the progress made in this area is very perceivable to the public. A new-generation Eurocopter helicopter flying over at 1,000 ft. altitude has a perceivable noise of 68 dB. Compared to regular road traffic, a car will be perceived at 72 dB and a motorcycle at 73 dB. In real life conditions, you will not hear a Eurocopter helicopter coming.
This is the result of continuous research into "quiet technologies" to which a large portion of R&D resources is devoted. Not stopping there, Eurocopter is working on further improvements.
Since the 1970s, the company has invested in consistently improving its unrivalled Fenestron® shrouded tail rotor technology, the latest generation of which is used for the EC120, EC130, EC135 and EC155. Compared to the original Fenestron® first featured on the Gazelle, a noise reduction of more than 5 dB on average has been achieved, equalling about 30 percent with regard to acoustic power perceivable.
Quiet main rotors are another focal point of Eurocopter’s R&D efforts. The company develops blades featuring evolutionary airfoils and reduced chord, with parabolic or tapered blade tips and evolutionary twist. Presently, research is done on the next generation of rotor blades with a view to lowering the noise at high speed and descent. The main rotor’s adaptable rotation rating is also targeted at reducing noise, while at the same time guaranteeing safety and maintaining high operational performance. In cooperation with engine manufacturers, Eurocopter is developing silent air intakes.
Noise abatement cannot only be achieved by new technologies developed by manufacturers. Every operator can "fly neighborly" by respecting recommended flight procedures. Eurocopter will include such recommendations on noise abatement in its flight manuals for its entire new-generation product line, allowing operators to significantly reduce the acoustic impact on the environment. The company cooperates with operators, citizens’ associations and authorities elaborating helicopter accessibility to urban areas.
One major program in this area is called "Friendcopter", a large-scale European project in which Eurocopter, AgustaWestland, European universities and research centers cooperate. Its aims are to propose a common European methodology for the minimalisation of neighbourhood annoyance; to elaborate low noise procedures for modern helicopters; and to elaborate a noise footprint calculation tool. As the "Friendcopter" program progresses, a flight test campaign is projected with three different helicopter types: the EC130, the EC135 and the A109.
In the next phase of the program, Eurocopter plans to become a recognised actor in the noise abatement field thanks to the results of "Friendcopter" and to become a partner in the definition of new operational procedures together with the FAA and ICAO. In cooperation with US manufacturers, Eurocopter also participates in the HAI’s "Fly Neighborly Workshop" as well as in ICCAIA (Association of Aeronautical Manufacturers) meetings involved in the land use planning program.
Noise abatement is a decisive factor in maintaining and increasing helicopter operations. Fully aware of that, and in close cooperation with its customers, Eurocopter will continue its efforts in this area to improve neighborhood acceptance for helicopters.
