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.