FAA’s Report to Congress (attached) on the use of the DNL metric had been released.
The attached document is the Federal Aviation Administration’s (FAA) report to Congress on an evaluation of alternative noise metrics as directed by the requirements of Section 188, “Study regarding day-night average sound levels”, of the FAA Reauthorization Act of 2018.
Section 188 of the Act directed the FAA to submit a report evaluating alternative noise metrics to the current average day-night level standard to the appropriate Congressional committees.
- The FAA reaffirms the use of DNL, finding that “Noise modeling is the only practical way to predict geospatial noise effects in a surrounding community when analyzing proposals related to aviation noise. Noise modeling is also necessary for a wide variety of other proposed federal actions, such as those resulting from airfield changes or changes in airspace management. The assessment of these actions requires the review of future case proposals and can therefore only be considered through predictive modeling.”
- The FAA also notes that “… while the DNL metric is FAA’s decision-making metric, other supplementary metrics can be used to support further disclosure and aid in the public understanding of community noise effects.”