A Noise Compatibility Study has several standard components which are required by Federal Aviation Regulations (FAR) Part 150. These components are listed below in the order that they occur. In addition to these elements, the Part 150 Noise Compatibility Study Update for Dayton International Airport included several items that went beyond the federally mandated scope. For a detailed project scope [click here]

Required Elements:

Inventory of Existing Conditions - Existing Airport facilities, operating practices, and activity levels are documented. Existing land use, planned land use and zoning maps and data are collected from municipalities surrounding the Airport in order to assess which land uses are compatible with existing noise levels (and potential future noise levels) and which land uses are not compatible.

Noise Measurements - Actual noise measurements are taken with sound measuring equipment in support of aircraft noise modeling. Measurements must taken with equipment having the "A" frequency weighting, filter characteristics, and the "slow response" characteristics as defined in International Electrotechnical Commission (IEC) Publication No. 179, entitled "Precision Sound Level Meters". (For more on acoustics and the A-weighted sound level see the Glossary).

Existing and Future Noise Exposure Impacts - Noise Exposure Maps (NEMs) are developed using the Federal Aviation Administration's Integrated Noise Model (INM). Five year future forecast noise is also predicted by the INM. (For more information on the INM, noise exposure maps and the DNL noise metric, please see the Glossary).

Future Noise Abatement/Noise Reduction Alternatives - Based on the information gathered in previous tasks, possible actions to reduce noise impact are analyzed and assessed for feasibility.

Future Noise Mitigation/Land Use Alternatives - Based on a review of land use and zoning information gathered during the inventory phase and discussions with local jurisdictions, possible actions to increase land use compatibility around the Airport are identified and analyzed.

Recommended Noise Compatibility Plan - The most promising noise abatement programs and noise mitigation options are combined into a recommended noise compatibility program (NCP).

Local jurisdiction and FAA Approval - Recommendations from the Study are presented to project committees and local jurisdictions for their review and comment. Those recommendations which the City of Dayton chooses to adopt will be submitted to the FAA for approval. Land use and zoning actions as a general rule are the purview of individual municipalities to implement if they desire.

The Dayton FAR Part 150 Noise Compatibility Study Update went beyond the requirements of FAR Part 150:

Noise Monitoring - The monitoring program designed for this study went well beyond what is required under FAR Part 150. Federal regulations require the use of the A-weighted decibel in noise compatibility studies. The FAR Part 150 Study Update for Dayton International Airport also examined low frequency noise events using the C-weighted decibel metric.

The scope of the airport noise monitoring program was extensive both geographically and in terms of the number of measurements that were taken. Two separate noise monitoring programs were conducted, so the role temperature variations and other seasonal variations (airport traffic levels) play in aircraft noise generation could be assessed.  The results of the noise measurement programs are posted on the What’s New page

Contours - The FAA mandates that contours be produced out to areas exposed to day-night average sound levels (DNL) of 65 A-weighted decibels (dBA). (Please see Glossary and Introduction to Acoustics for a full explanation of these terms.) Since many residents around airports feel strongly that noise below DNL 65 is still troublesome this study addressed aircraft noise levels of  DNL 60-65.

Third Runway - A future long-range (20 year forecast) noise contour map was developed to allow a first look at the impacts of the potential third parallel runway in terms of noise exposure.

Recommendations - Some possibilities which have emerged from this study are beyond the parameters of a Part 150 Study and will require additional consideration and analysis by both the City of Dayton, local jurisdictions, and the FAA. Items of this nature will not be dropped, and will be retained for further consideration.

Public Participation - FAR Part 150 suggests that there be an Advisory Committee and that a Public Hearing be conducted at the end of the noise compatibility planning process. The public involvement component of the FAR Part 150 Update conducted for Dayton International Airport has included: multiple meetings with three project committees, public workshops, special briefings to elected officials, newsletters, and this Web Page.