AICUZ Overview

AICUZ Program
Air Installations Compatible Use Zones (AICUZ) is a program concerning people, safety, and protection. This brochure summarizes the 2018 AICUZ Study for Hill Air Force Base (AFB), Utah. The AICUZ Program is an extensive analysis of the effects of aircraft noise, aircraft accident potential, and land use development upon present and future neighbors of Hill AFB. The AICUZ Program seeks a cooperative understanding and a reasonable solution to this intricate situation. The 2018 AICUZ Study provides an update to the previous 1993 AICUZ Study and documents changes in flight operations, noise contours, and compatible use guidelines for land areas surrounding Hill AFB.

Noise Zones and Noise Metric
Under the AICUZ Program, the DoD provides noise zones as a planning tool for local agencies. Noise exposure is measured using the Day-Night Average Sound Level (DNL). The DNL metric is based on the number of annual average daily aircraft operations over a 24-hour period. The DNL includes a 10 decibel (dB) adjustment, or penalty, for aircraft noise occurring between 10 p.m. and 7 a.m. because people are more sensitive to noise during that period. DNL has become the standard metric used by many government agencies and organizations, including the U.S. Environmental Protection Agency (EPA) and the Federal Aviation Administration (FAA) for addressing aircraft noise. The map to the right displays the relevant DNL contours over existing land use. Under the existing land use there are 678 acres of incompatible development within the 65 dB DNL contour. Under future land use, incompatible land development may increase within the 65 dB DNL contour as residentially zoned lands are developed.

Accident Potential Zones
The DoD provides Accident Potential Zones (APZs) as another planning tool for local agencies. APZs are where an aircraft accident is likely to occur, if one occurs. However, they do not reflect the probability of an accident. APZs extend 15,000 feet from the end of each runway along the runway’s extended centerline. It should be noted that flight tracks are not roadways in the sky. Weather conditions, wind, pilot technique, and other air traffic will cause some lateral deviation within the landing pattern around an airport. The map to the right displays the relevant APZs. Under existing land use, there is 293 acres of incompatible land development within the APZs. Under the future land use planning, incompatible land development within the APZs may decrease as cities redevelop property with compatible uses.

Hazards to Aircraft Flight Zone
Certain land uses and activities can pose potential hazards to flight. To ensure land uses and activities are examined for compatibility, the Air Force has identified a Hazards to Aircraft Flight Zone (HAFZ). The HAFZ is defined as the area within the “Imaginary Surfaces” that are described in the UFC 3-260-01, and in 14 CFR Part 77.17. Unlike Noise and Safety Zones, the HAFZ does not have recommended land use compatibility tables. Instead, it is a consultation zone for the purposes of project applicants and local planning bodies to consult with the Air Force to ensure the project is built compatibly. These land uses and activities include:

Additional hazards to flight safety include:

• Uses that would attract birds, especially waterfowl;
• Towers, structures, and vegetation that penetrate navigable airspace or are to be
constructed near the airfield;
• Lighting (direct or reflected) that would impair pilot vision;
• Uses that would generate smoke, steam, or dust; and
• Electromagnetic interference (EMI) with aircraft communication, navigation, or other electrical systems.

Land Use Compatibility
In general, the Air Force land use compatibility guidelines, as outlined in Air Force Instruction (AFI) 32-7063, recommend that noise-sensitive land uses be placed outside high-noise zones and people-intensive uses not be placed in APZs. Certain land uses are considered incompatible with APZs and high-noise zones, while other land uses may be considered compatible or compatible under certain conditions (compatible with restrictions). Land use development should be compatible with noise zones and APZs around a military airfield. Although the military can serve in an advisory capacity, local governments control the development beyond the boundaries of Hill AFB.

Summary of AICUZ Recommendations

• Continue to incorporate AlCUZ policies and guidelines into the comprehensive plans of Davis and Weber counties and the nearby cities. Use overlay maps of the AICUZ noise contours and Air Force Land Use Compatibility Guidelines to evaluate existing and future land use proposals.

• Monitor any subdivision regulations in Davis and Weber counties and the nearby cities related to noise level reduction based on current noise contours and update the regulations if necessary.

• Continue to inform Hill AFB personnel of planning and zoning actions that have the potential of affecting Hill AFB operations. Maintain the working group of city/county planners and base planners that regularly meets to discuss AICUZ concerns and major development proposals that could affect airfield operations.

• Modify existing zoning ordinances and subdivision regulations in Davis and Weber counties and the nearby cities to support the compatible land uses outlined in this study.

• Modify building codes within Davis and Weber counties and the nearby cities to ensure new construction within the AICUZ area has the recommended noise level reductions incorporated into its design and construction.

• Continue to implement height and obstruction ordinances that reflect current Air Force Title 14 Code of Federal Regulations Part 77 requirements.

Stay Connected



What's been done?

Hill AFB has placed restrictions on flying activities that could adversely affect its neighbors in an effort to reduce noise impacts while maintaining safe operations. Hill AFB has also demonstrated a spirit of cooperation by consulting with local communities in the area-wide planning process relating to land use near the base. Davis and Weber counties and the nearby cities have also played a major role by supporting the Hill AFB AICUZ Program in its ongoing planning and zoning decisions. Continued cooperation between Hill AFB, the local authorities, and local populace around the base will further reduce potential land use conflicts. This action will also help to ensure that future land uses are compatible and beneficial.

The benefits?

In addition to protecting the public health and safety, other benefits provided by Hill AFB include protecting the taxpayer’s investment in national defense and protecting economic benefits to the surrounding communities. The local economy is enhanced by Hill AFB’s expenditures for salaries, contracts, construction, retirement pay, tuition aid to schools, health insurance payments, and off-installation accommodations for travelers. In terms of total economic impact in the region, Hill AFB employs more than 21,100 military and civilian personnel. These jobs have an estimated total economic impact of nearly $3.4 billion resulting from payroll expenditures, annual expenses, and the estimated value of indirect jobs in the local area. Hill AFB is a strong partner in the economic future of the region.

How can I help?

Historically, citizens of Davis and Weber counties and the nearby cities and personnel from Hill AFB have cooperated to better serve the needs and desires of all concerned. The Air Force has developed strategies intended to maximize the benefits of Hill AFB while minimizing annoyances. If the future of Hill AFB is to be as bright as its past, you, the citizens of this area, need to participate in the process of achieving a suitable resolution of our mutual concerns. We request your careful review of the Hill AFB 2018 AICUZ Study recommendations.

Sound / Real Estate

Sound Insulation
Constructing a new building, structure, or an addition to an existing building must comply with the Utah Building Code. The AICUZ Program, as specified in AFI 32-7063, has noise attenuation recommendations. Some local governments have adopted sound attenuation requirements consistent with Guidelines for Sound Insulation of Residences Exposed to Aircraft Operations (Ehrlich et al., April 2005). Local enforcement of these requirements helps to minimize the impact that noise has on building inhabitants.

Real Estate Disclosure
There is no formal disclosure of military operations required by law, but the Air Force recommends buyers be aware of noise zones and APZs near military airfields.

Review AICUZ Study

For more information on the Hill AFB 2018 AICUZ Study, contact the Hill Public Affairs Office at 801-777-5201 or email

Noise concerns

Review the Noise FAQs.

You can also email or call toll free 877-885-9595. Please take note of the date, time, location, and type of aircraft (if known) to allow Hill personnel to best assist with noise concerns.