Sound land use planning requires accurate predictions of the acoustic signatures at noise-sensitive receiver points and methods for interpreting the effect of acoustic signatures on public health, safety, and welfare. Historically, the study of noise impacts from aviation has been focused on fixed-wing aircraft, while the complexity of helicopter and new-technology rotary-wing aircraft has not been given adequate attention.The FAA Integrated Noise Model (INM) is currently the agency’s required tool for NEPA-related studies and FAR Part 150 studies. The Heliport Noise Model Version 2.2 was recently incorporated into INM Version 7.0 with a helicopter noise database collected through both FAA and manufacturer certification measurements. Currently, the FAA is incorporating INM, along with emission and fuel burn calculation methodologies, into the Aviation Environmental Design Tool (AEDT). The fixed-wing aircraft noise prediction techniques employed in INM/AEDT rely on the widely accepted methodologies described in documents such as SAE International’s SAE-AIR-1845 and the European Civil Aviation Conference’s Document 29. However, in contrast to guidance related to fixed-wing aircraft, there is no peer-reviewed guidance document describing an integrated modeling technique for the prediction of helicopter noise.Research is needed to document current practice, improve modeling methods, and provide guidance for using INM/AEDT to predict helicopter noise.
The objective of this research is to review, evaluate, and document current helicopter noise models and identify potential improvements to INM/AEDT to better capture the unique complexity of helicopter operations. The research should include:
(1) A listing of relevant domestic and international literature with abstracts where available; (2) A review of the methods (e.g., inputs, assumptions, algorithms, database coverage, outputs, methods of estimating uncertainty) and validation history of existing noise models used for predicting helicopter noise, including, but not limited to, HNM/INM/AEDT and the Rotorcraft Noise Model; (3) An assessment of the strengths and weaknesses of each method’s ability to capture the unique noise characteristics of helicopter operations, including takeoffs and landings at airports and heliports, overflights, hovering, and orbiting; (4) An assessment of the strengths and weaknesses of each model’s user experience (e.g., database availability and accuracy, user interface, runtime, output) relative to modeling helicopter activity; (5) A prioritized list of potential improvements to INM/AEDT, including options for incorporating new technology aircraft (such as tilt rotors), and a subset of near-term, high-priority improvements for immediate development and incorporation into INM/AEDT that would result in more accurate predictions of helicopter noise; (6) Detailed documentation of the near-term, high-priority improvements to INM/AEDT that would result in more accurate predictions of helicopter noise;(7) A peer review of the detailed documentation of the near-term, high-priority improvements to INM/AEDT; (8) A supplemental document to the User Guide of INM/AEDT, providing guidance for modeling and presenting helicopter noise prediction data, similar in format to the European Civil Aviation Conference’s Document 29, Volume 1; (9) A work plan and cost estimate to undertake the research necessary to develop the remaining improvements; and (10) Research ideas, in the form of ACRP problem statements, proposing research to:
- Improve the understanding of community response to helicopter noise,
- Develop guidance for incorporating helicopter operations into land use planning/zoning, and
- Address other research needs identified during the study.