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Noise Modelling

The following maps provide the sound contours related to current aircraft operations as well as those projected to occur with proposed changes. These contours were developed using a noise model application developed by the Federal Aviation Administration (FAA) and recommended by the International Civil Aviation Organization (ICAO).

The contours show the cumulative sound impact of operations using the Day-Night Level (DNL) metric. The DNL metric is widely used as a measure to communicate a cumulative exposure to aircraft noise, using a 24-hour average. The metric assists with the comparison of different aircraft operations, such as those expected before and after an airspace change.

The DNL metric takes all the aircraft noise events at a location and averages them to provide a single numerical value. This allows for comparison between one location that experiences a handful of very loud events in a day against another that may receive more events that are not as loud. The metric also applies a penalty to operations between 10 p.m. and 7 a.m. to recognize lower community ambient noise levels at those times.

Due to the volume of traffic and runway variance at Ottawa Macdonald-Cartier International Airport, all of the cumulative exposure above 50 DNL occurs at locations where aircraft are on final approach.

The following map provides the contours for current operations:
The following map shows what the cumulative impact would be if the proposed changes were implemented in 2016:

To learn more about RNP, access “The Basics of RNP

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