What is a Part 150 Study?
Part 150 is a section of the Federal Aviation Regulations (FAR) that sets forth rules and guidelines for airports desiring to undertake airport noise compatibility planning. The Part 150 establishes guidelines for technical aspects of aircraft noise analysis and the public participation process for airports choosing to prepare airport noise compatibility plans.
Part 150 Study involves six major steps:
- Identification of airport noise and land use issues and incompatibilities;
- Definition of current and future noise exposure contours;
- Evaluation of alternative measures for abating noise that impact the 65 Day Night Level (DNL) noise contour (e.g., changing aircraft flight paths), mitigating the impact of noise (e.g., sound insulation), and managing local
- land uses (e.g., airport-compatible zoning);
- Development of a Noise Compatibility Plan (NCP);
- Development of an implementation and monitoring plan; and
- FAA review and approval of the recommended NCP, including the analysis of alternatives, the compatibility plan, and the implementation and monitoring plan.
The Part 150 Study process is designed to identify noise sensitive land uses surrounding an airport, and to recommend measures to both correct existing incompatibilities and to prevent future incompatibilities. For Part 150 Study purposes, noise sensitive land uses are generally defined as residences or public use facilities (libraries, churches, schools, nursing homes and hospitals) within the 65 Day-Night Average Sound Level (DNL) noise contour, the area the FAA defines as impacted by aircraft noise.
Why prepare a Part 150 Study?
The purpose for conducting a Part 150 Study at an airport is to develop a balanced and cost-effective plan for reducing current noise impacts from an airport’s operations, where practical, and to limit additional impacts in the future. By following the process, the airport operator is assured of the FAA’s cooperation through the involvement of air traffic control professionals in the study and the FAA’s review of the recommended Noise Compatibility Program (NCP). The decision to undertake noise compatibility planning is normally voluntary on the part of the airport operator.
An airport with an FAA-approved NCP also becomes eligible for funding assistance for the implementation of approved measures.
Among the general goals and objectives addressed by a Part 150 Study are the following:
- To reduce, where feasible, existing and future noise levels over existing noise-sensitive land uses;
- To reduce new noise-sensitive developments near the airport;
- To mitigate, where feasible, adverse impacts in accordance with Federal guidelines;
- To provide mitigation measures that are sensitive to the needs of the community;
- To minimize the impact of mitigation measures on local tax bases; and
- To be consistent, where feasible, with local land use planning and development policies.
How long will the Part 150 Study take to complete?
The Duluth Airport Authority (DAA) began early coordination of the Part 150 study in August 2019, and consultant team began work in September 2019. The study is scheduled for completion in 2020 and will be submitted to the FAA for review. The review period by the FAA is typically 6-9 months. Implementation of the study recommendations will be based on review and approval of the NCP by the DAA and the FAA.
What are some examples of mitigation measures?
At a minimum, a Part 150 Study shall analyze and report on the following alternatives, subject to the constraints that the strategies are appropriate to the specific airport (for example, an evaluation of night curfews is not appropriate if there are no night flights and none are forecast):
- Acquisition of land and interests therein, including, but not limited to air rights, easements, and development rights, to ensure the use of property for purposes which are compatible with airport operations.
- The construction of barriers and acoustical shielding, including the soundproofing of public buildings.
- The implementation of a preferential runway system.
- The use of flight procedures (including the modifications of flight tracks) to control the operation of aircraft to reduce exposure of individuals (or specific noise sensitive areas) to noise in the area around the airport.
- The implementation of any restriction on the use of an airport by any type or class of aircraft based on the noise characteristics of those aircraft. Such restrictions may include, but are not limited to—
- Denial of use of the airport to aircraft types or classes which do not meet Federal noise standards;
- Capacity limitations based on the relative noisiness of different types of aircraft;
- Requirement that aircraft using the airport must use noise abatement takeoff or approach procedures previously approved as safe by the FAA;
- Landing fees based on FAA certificated or estimated noise emission levels or on time of arrival; and
- Partial or complete voluntary curfews.
- Other actions or combinations of actions which would have a beneficial noise control or abatement impact on the public.
- Other actions recommended for analysis by the FAA for the specific airport.
What are Noise Exposure Maps (NEM)?
Noise Exposure Maps (NEMs) identify the noise exposure of the current operating conditions, and projected future conditions. Included within this analysis will be the operating conditions taking place at the airport including departure and arrival procedures, daytime and nighttime activity, touch and go operations and helicopter activity.
What is DNL?
The Day-Night Average Sound Level metric describes the total noise exposure during a given period. DNL is a metric used for predicting the average long-term noise exposure on a population. In computing DNL, an extra weight of 10 dB is assigned to any sound levels occurring between the hours of 10:00 p.m. and 7:00 a.m. This is intended to account for the greater annoyance that nighttime noise is presumed to cause for most people. This extra weight treats one nighttime noise event as equivalent to 10 daytime events of the same magnitude.
What is AEDT?
The FAA has developed the Aviation Environmental Design Tool (AEDT) for evaluating aircraft noise impacts in the vicinity of airports. AEDT is a software system that models aircraft performance in space and time to estimate fuel consumption, emissions, noise, and air quality consequences. AEDT has been updated numerous times since its implementation, and Version 3b will be used to develop the noise modelling for this Part 150 Study. The FAA requires the use of AEDT to develop noise exposure contours in Part 150 Studies.
AEDT utilizes flight track information, aircraft fleet mix, and aircraft flight profiles and terrain as inputs. AEDT produces noise exposure contours that are used for Noise Exposure Maps (NEMs).
What is the purpose of noise monitoring?
Field measurements from the short-term noise monitoring program will be collected for use in the study. The measurements are compared with pre-existing database information related to aircraft noise level and performance characteristics in AEDT. The information collected during the measurement program includes acoustical output, as measured at known locations, as well as flight trajectory data (the aircraft’s three-dimensional location) relative to the noise measurement site. This information will be used to ensure that the input data into the AEDT is as accurate as possible.
Can the Duluth Airport Authority restrict operations on its runways?
No, the FAA is the only entity that can manage aircraft runway operations or aircraft in flight at DLH.
Can the Duluth Airport Authority recommend implementing aircraft noise restrictions?
If recommended, the DAA could request airlines and other airport users to voluntarily restrict the use of certain types or aircraft. All options would need to result in a reduction in the noise impacts at DLH before being recommended in the Part 150 Study and\or implemented by the DAA.
In order to implement mandatory restrictions on aircraft a separate Part 161 Study (Notice and Approval of Airport Noise and Access Restrictions) would need to be conducted. To date, no Part 161 Study has been approved by the FAA.
Can the Duluth Airport Authority recommend implementing operating curfews?
If recommended the DAA could request airlines and other airport users adopt a voluntary curfew. It should be noted curfews are typically used as a last resort, when all other options have shown to be less than adequate, due to the drastic negative impacts upon both aviation and the community’s benefit from aviation. All options would need to result in a reduction in the noise impacts at DLH before being recommended in the Part 150 Study and\or implemented by the DAA.
In order to implement mandatory curfews at an airport, a separate Part 161 Study (Notice and Approval of Airport Noise and Access Restrictions) would need to be conducted. To date, no Part 161 Study has been approved by the FAA.
Where does the Duluth Airport Authority receive funding for noise mitigation projects?
When noise mitigation programs are approved by the FAA through a formal Part 150 Study, those programs then become eligible to receive FAA Grant funding of up to 80%. The remainder of the funding comes from the Duluth Airport Authority, from revenues generated at the airport (parking fees, landing fees, leases, etc.).
What types of noise mitigation projects can the Duluth Airport Authority spend funds on?
Any noise reduction related project approved by the Duluth Airport Authority (DAA) and the FAA through a Part 150 Noise Study that demonstrates how it will have a measurable impact on noise can qualify for FAA funding and for DAA funding.
For example, home insulation projects inside the 65 DNL Contour, the FAA-established noise impact area that determines insulation eligibility, would qualify if approved by the FAA through the Part 150 Noise Study. FAA funding sources come with a number of stipulations and conditions that the DAA agrees to when accepting funds. Additionally, the same FAA conditions would prevent the DAA from using the revenues it generates at the airport (parking fees, landing fees, etc.) for projects that are unable to demonstrate a measurable community impact on noise.
Qualifying for FAA grants is the first step. Other steps include an environmental review of the proposed action, obtaining the grants from the FAA and receiving DAA approval authorizing the use of available airport funds.
What results can communities around DLH expect from the new Part 150 process once it is complete?
The current Part 150 Study is underway. As part of their works, consultants will develop new noise maps showing how the airport’s overall noise affects the community now and in the future. The consultant will conduct a wide-ranging review of all the Airport’s noise reduction efforts and evaluate new ways to improve upon existing efforts. Through public workshops, the public will be able to identify and shape the noise recommendations that will be included in the Part 150 Study. The Duluth Airport Authority (DAA) has committed to a thorough and accessible public process throughout the Part 150 Study that will ensure there are multiple avenues for involvement and public comment.
How can I get involved with the Part 150 Study as it progresses and where can I find information?
A series of public workshops will be held at key milestones during the Part 150 Study. Open to all, each workshop is designed to make it easy for the public to provide input, ask questions and offer recommendations in a more personal setting. Click here for additional information on public meetings. To keep up to date throughout the Part 150 process, sign up to receive email updates here.