18 Apr Choose your noise mitigation measures wisely
In this final blog of our series on aircraft noise exposure around Europe’s largest airports, we explore noise mitigation measures and how they could potentially provide immediate improvements for the surrounding communities. The choice of mitigative measures needs to be considered carefully, however. After all, each airport is unique, and the most effective measures will be those tailored to the specific situation.
Ultimately, the goal is optimal noise relief for the surrounding community
Effective aircraft noise mitigation measures
Air navigation service providers and airports are increasingly focused on reducing the aircraft noise footprint. As we noted in our first blog, a critical first step in effective aircraft noise mitigation is determining which community to target. Because different noise reduction measures are more effective at different distances, the choice will depend largely on the affected population’s distance from the airport. Let’s look at three possible measures.
PREFERENTIAL RUNWAY USE
A relatively straightforward way to provide noise relief to communities close to the airport is by designating preferred runways or alternating runways at certain times.
At London Heathrow, for example, alternation provides periods of noise relief for surrounding communities by switching landings and take-offs between runways. This spreads the aircraft noise impact more evenly.
HIGH PRECISION NAVIGATION
High performance-based navigation techniques like Required Navigation Performance (RNP) can help reduce the aircraft noise footprint. Contrary to traditional navigation where flight tracks are widely dispersed, RNP enables aircraft to navigate with high accuracy over a predetermined departure or arrival route, creating more lateral precision. The resulting noise concentration could be configured to affect the least amount of people, most effectively at a medium distance from the airport.
Runway 14 at Australia’s Gold Coast Airport is an excellent example. Originally, the approach followed the heavily-populated coastline. Since Air Services Australia implemented Smart Tracking and RNP, aircraft now fly most of their approach over the sea, with positive community response as a result.
The RNP approach has an additional benefit of reducing the flight path by about 15nm, thus lowering fuel burn (approx. 200 kg/flight) and emissions (950 tonnes/year CO2).
NOISE ABATEMENT DEPARTURE PROCEDURES
As another effective method, Noise Abatement Departure Procedures can mitigate aircraft noise nuisance by prescribing engine and flap settings and the order of aircraft take-off operations. The chosen procedure might specify using engine thrust to gain altitude initially and increase velocity later or, conversely, to accelerate first, then climb.
The first option offers noise relief close to the airport, whilst the second option is quieter further away. Whether option one or option two is preferable depends then on the location of communities in relation to the departure route.
Choosing the most effective solution
Developing an effective noise mitigation action plan requires careful analysis of the situation-specific effects of possible measures to help find the most suitable (combination of) solutions for the airport and its surroundings.
In our aircraft noise mitigation projects, we work a lot with evaluating aircraft noise mitigation measures by calculating and analysing noise contours and creating radar heat maps in both before and after scenarios. This gives us insights into the effects on noise exposure that can help determine which measures will work best. Ultimately, the goal is optimal noise relief for the surrounding community.
In our first blog of this series, we presented our analysis of aircraft noise exposure around the largest airports in Europe, which revealed important considerations about the growing attention on negative effects of aviation on the environment. The second blog examined the challenges for authorities in balancing airport growth and the needs of the community.
About To70. To70 is one of the world’s leading aviation consultancies, founded in the Netherlands with offices in Europe, Australia, Asia, and Latin America. To70 believes that society’s growing demand for transport and mobility can be met in a safe, efficient, environmentally friendly and economically viable manner. To achieve this, policy and business decisions have to be based on objective information. With our diverse team of specialists and generalists to70 provides pragmatic solutions and expert advice, based on high-quality data-driven analyses. For more information, please refer to www.to70.com.