Federal Aviation Authority Advisory Circular (AC) 150/5020-1
Noise Control and Compatibility Planning
Eric v. Walker
Embry Riddle Aeronautical University
ASCI-617 Airport Safety and Certification
01 October, 2012 ABSTRACT
This paper attempts to summarize key points such as the purpose, intent, and contents of the Federal Aviation Authority (FAA) Advisory Circular 150/5020-1 on Noise Control and Compatibility planning for Airports. The effect of noise on communities around the United States and has been a well-publicized concern of both airport managers and legislatures from both local and national levels. The federal government has been addressing the issue from as early as the 1920’s, but demand for change in the effects of airport and airplane related noise truly came to the forefront with the growth of use in jet engine driven aircraft and vast increases in air travel across the country. Today, the primary objective is to create a cooperative environment where airports, communities, professionals, and legislatures work as a team in utilizing the available mitigating options to ensure noise is much less of an irritant and well-managed in relation to land use in and around airports. Advisory Circular (Ac) 150/5020-1
Noise Control and Compatibility Planning

Federal Aviation Regulation (FAR) Part 150 is the governing document provided to establish and sustaining guidelines to be used by airports in planning for expansion and development. The FAR Part 150 is based on and implements the Aviation Safety and Noise Abatement Act (ASNA) of 1979. The ASNA is the basis for establishment of a single system for measuring airport noise; need to measure compatibility of land use; and provided for financial incentives to motivate both aircraft and airport operators to develop and adopt anti-noise policies (Falzone, 1999). Oddly, noise plans and compatibility studies driven from this legislation are not mandatory for airports governed by the FAA, they are considered totally voluntary. The regulation allows airport operators to voluntarily submit noise exposure maps and noise compatibility programs to the FAA for review and approval. A noise compatibility program sets forth the measures that an airport operator “has taken” or “has proposed” for the reduction of existing incompatible land uses and the prevention of additional incompatible land uses within the areas surrounding the airport (FAA, 2012).

In applying the FAA Part 150 to Airport Noise Compatibility Planning programs airport operators can go to the FAA’s Advisory Circular (AC) 150/5020-1 for program specifics. Within the AC 150/5020-1 are the specifics and a general step by step process for meeting the intent of the FAA Part 150. It is broken into sections which describe general information, methods for noise measurement and assessment, and tools for airport noise compatibility planning.

PURPOSE OF NOISE PLANNING EFFORTS
Over the past 50 years the general public attitude toward use of land surrounding many airports has changed dramatically. At one time it would have been hard to imagine wanting to live within shouting distance of an airport simply for the fact that there would be an expected level of noise that came with living near an airport. Yet today, the five to ten miles of property directly surrounding airports that used to be barren land is now frequently occupied by residential and commercial properties. This is mostly an effect of local and state laws that do not restrict the use of this land from being used for the benefits of the local communities.
Driving the efforts placed in noise issues is the effect on people who live, work and study near airports. Numerous studies have been accomplished to measure the effect of noise on those living near airports and often more than not, the results show there is an expectancy that noise from airports will exist due to the proximity of location to the airport but, there is a measurable level of annoyance by the ascent and descent of aircraft arriving and leaving airports.
Additional Research indicates that excessive noise can cause significant health problems, such as hearing loss, hypertension, cardiovascular disease, gastrointestinal problems, and other disorders.32 In addition, noise may cause interference with communication, sleep deprivation, poor performance at work and in school due to of lack of concentration, and general annoyance (Falzone, 1999).
When airport operators, state and local planners, community leaders, and local proprietors are planning and developing in and around airports they can and should use the AC 150/5020-1 as a guide in reducing noncompatible land use and preventing additional noise related issues from arising. It is intended for use by airport operators, state/local planners and other officials, and interested citizens who may engage in noise control planning. Airport noise compatibility planning has the goals of reducing existing noncompatible land uses around airports and of preventing the introduction of additional noncompatible land uses through the cooperative efforts of all those involved. There are already a number of efforts in place which help limit the growth of noise compatibility problems in the U.S. to include limits placed on aircraft manufacturers in meeting noise emission standards for new aircraft, the retrofit of quieter engines on transport aircraft, and mandated environmental studies for proposed development projects around FAA governed airports. Even with all of these management tools in place instrumental to this process is the fact that the FAA does not have the authority or responsibility of setting land use controls or placing restrictions in and around airports in the matter of land use; this action rests with local and state governments, especially those who are independent airport authorities.

NOISE COMPATIBILTY
According to the FAA noise is the greatest threat to aviation due to projected growth and demand for air travel which will drive increased air carrier presence at major and general use airports (FAA, 2012, p.2). Inevitably the increased air traffic will result in increased complaints from local residents and businesses. The FAA also acknowledges that there are adverse effects of noise which they classify as 1) degradation of health, 2) attitudinal reactions, and 3) activity interference. Through Airport Noise Compatibility Planning the FAA seeks to create joint planning efforts which examine and weigh both aviation and urban planning strategies in existing and future noise conflicts around airports (FAA, 2012).
The purpose of the FAA’s AC 150/5020-1 is to provide airport operators an avenue to preserve the national airport system integrity by creating compatibility with local neighborhoods. The objective of the AC 150/5020-1 is to provide clarity in meeting requirements the FAA Part 150 Noise Compatibility Planning Program which include:
(1) A balanced approach producing realistic and practical solutions fair to both aviation and non-aviation interests.

(2) Positive FAA technical guidance through regional and airports district offices.

(3) Federally identified land uses which are normally compatible with various exposures of individuals to noise.

(4) Consultations and interactions between the airport operator, airport users, airport neighbors, local land use control jurisdictions, and the FAA designed to achieve broad-based confidence in and acceptance of the program and the support essential for its implementation over the long term.
(5) Recognition of factors beyond the control of the airport operator which strongly influence local land use decisions.

(6) A viable framework for conducting efficient and constructive compatibility programs which achieve large benefits in noise reduction for the costs in aviation.

(7) Community and airport operator decisions that are made from a fully informed position in order to weigh the full costs and benefits of the alternatives.

(8) Federal financial assistance available to the airport operator under the Airport Improvement Program for noise compatibility planning and for implementation of that planning.

(9) Federal financial assistance also available to units of local government in the area surrounding the airport to carry out projects in accordance with FAA approved noise compatibility programs.

(10) Certain sanctions are available under Section 107 of the ASNA Act to protect the airport operator from land owner noise suits.

Since the flight patterns for most airports have been well established and most land usage already known it is generally easy to determine noise contours which show where noise levels are in relation to airports.

MEASURING AND ASSESSING NOISE
The FAA recognized there are no two airport situations for which one method of mitigating measures will suffice and that whether it be a school, church, residence, factory, warehouse or open farmland each will have a differing level of sensitivity to the surrounding noise. In order to assist airport and community planners, the FAA provides a table of land uses and compatibility/non-compatibility with varying noise level as a section of the AC 150/5020-1 (Table 1). There are two methods in use to determine noise levels in communities around airports. First, evaluators must map the geographical areas which are exposed to specific noise levels and then determine the length of time at which those areas are exposed to measurable levels of noise to help develop noise contours around the airport. The primary noise factors measured in the study of community noise related to airport operations are the types of aircraft utilizing the airport, the number of overall takeoffs and landings, the specific runways used for aircraft operations, weather conditions, existing flight procedures at the airport, and the time of day or night aircraft operate (NOISE, Unknown). Fig1. Current INM computer based model Fig 2. Current INM computer based model

Because it would take noise measuring equipment placed in multiple locations over extensive periods of time to develop true contours from measureable data and at an extremely high expense, many airports utilize computer-based mathematical models such as the FAA’s Integrated Noise Model (INM) to measure the impact of airport activity and as a means of predicting noise contours for an area or noise level at pre-selected locations (Fig 1 & Fig 2).
The noise output can be exposure-based, maximum-level-based, or time-based. It is developed based on the algorithm and framework from SAE AIR 1845 standard, which used Noise-Power-Distance (NPD) data to estimate noise accounting for specific operation mode, thrust setting, and source-receiver geometry, acoustic directivity and other environmental factors (FAA-INM, 2012).
By measuring noise levels across areas over longer periods vice just measuring single flight events it is possible to determine the Community Noise Equivalent Level (CNEL), which is essentially a measurement of ambient noise using different weight factors for day, evening, and late night periods. This recognizes that community members are most sensitive to noise in late night hours and are more sensitive during evening hours than in daytime hours (Mather Field, 2003). Understanding the noise levels experienced within the regions surrounding the airfield enables understanding of how noise affects the community and helps developers plan for the future when deciding where to locate public entities which are sensitive to noise levels.
ACHIEVING COMPATIBLE LAND USE Since flight patterns fir airports are generally well-known, noise contours easily identifiable and land uses pretty well understood it behooves community managers to make known the potential for elevated noise exposure before development and improvement projects are even started. Working in collaboration with planners, zoning regulators and development groups enables airport mangers and authorities to develop a greater level of compatibility between the airport and the surrounding community (ACRP, 2009).
As a means of achieving the intent of Part 150 and the specifics of the AC 150/5020-1 Advisory, The federal government provides funding in the form of the Airport Improvement Program (AIP) and the Passenger Facility Charge (PFC) Program dollars to public and sometime private entities planning and executing projects which will meet noise compatibility objectives. Eligible projects include those improvements which are directly related to enhancing the safety, capacity, security and environmental concerns of an airport community. Large and medium airports are eligible for up to 80 percent of the cost for noise related program implementation and smaller general airports can receive as much as 90-95 percent based on statute limitations (FAA-AIP, 2012). There are options available to the airport, the local and state government and the community when considering how to mitigate the impact of airport noise. For airport operators the more restrictive options include denying use of the airfield to aircraft not meeting federal noise standards per the FAR Part 36, setting capacity limitations on the airfield and a means of reducing the amount of noise at any given time, reducing operating in order not to exceed the cumulative maximum noise exposure level.
The most probable mode of effective measures taken in relation to flight operations is noise abatement in relation to takeoff and approach procedures. Within this approach the alternatives include runway selection, takeoff and landing profiles and power settings, and approach and departure paths. (FAA, 2012, chap-3, Pg 30). Secondly, for ground level noise airports have the ability to use hush-houses, sound barriers, and strategic placement of maintenance, run-up, and warehousing areas as a means of managing noise. Finally, another strategic planning tool is the partial or total purchase of the land adjacent to the airport property. Although extremely costly in some instances this method protects the airport and enables future development which could enhance the airports long-range capability.
The government agencies can use zoning and easements as tools to control development in and around airports, strategic location of public work projects, sound-proofing, a purchase assurance programs for residential properties located in noise impacted areas, and as well the purchase of noise impacted lands. The FAA recognizes the community and the airport share economic, environmental, and social influences over each other and feels the most productive means available to the local community is direct involvement in the planning and understanding of airport projects early on in the process.
The FAA AC 150/5020-1 is simply a guiding document for planning and controlling noise related issues near airports, but the true power in how land usage is enacted, rests in the hands of state and local community managers. In accordance with the Part 150, airport operators are to summarize and document public procedure and input processes for the Noise Compatibility Program. Achieving agreeable outcomes to noise impacting projects and improvements is a measure of economic and social impacts to both the airport and the community. Providing the sense of increased safety coupled with a diminished noise level is the ultimate level of satisfaction for the community. To this end it is important that airport managers identify the specific issues impacting noise level near area airports through environmental impact studies and usage assessments, then clearly identify what information must be communicated to the public, which groups need to know the information, what information needs to be received from the public, and from whom the information can be obtained. (FAA, 2012, chap-3, pg 40).
When the airport, local, State and federal entities work together and address noise related issues as directed under Part 150 and following the specific guidance derived from the FAA AC 150/5020-1 it is possible to achieve the best result for both the airport and local community while sustaining growth, expansion, and development of the airport system. REFERENCES
49 USC CHAPTER 475 – NOISE. Title 49 – Transportation, Subtitle VII - Aviation Programs Part B - Airport Development and Noise. Retrieved online at http://uscode.house.gov/download/pls/49C475.txt

ACPR – Airport Cooperative Research Program (ACRP), (2009). Aircraft Noise: A Toolkit for Managing Community Expectations. Retrieved online at http://onlinepubs.trb.org/onlinepubs/acrp/arcp_rpt_015.pdf
FAA PTF, 2012. Planning Task Force. Land Use Compatibility and Airports http://www.faa.gov/about/office_org/headquarters_offices/apl/noise_emissions/planning_toolkit/media/III.B.pdf
Falzone, Kristin L. (1999). Airport Noise Pollution: Is There a Solution in Sight?, 26 B.C. Envtl. Aff. L. Rev. 769. Retrieved online at www.lawdigitalcommons.bc.edu /ealr/vol26/iss4/8

FAA INM, 2012. Integrated Noise Model. Retrieved online at http://www.faa.gov/about/ office_org/ headquarters_offices/apl/research/models/inm_model/

FAA AIP, 2012. Airport Improvement Program. Retrieved online at http://www.aff.gov/ airports/aip/overview/

Mather Field Noise Studies: Community Noise (CNEL) Measurements. Retrieved online at http://www.sierrafoot.org/local/noise/cnel.html

Noise, unknown. Approach to Aircraft Noise Measurement. Derived from Chapters 3-4, Aviation and the Environment: FAA's Role in Major Airport Noise Programs. U.S. General Accounting Office, GAO/RCED-00-98 (April 2000). Retrieved online at http://airportnoiselaw.org/faanoise.html