The following definitions shall apply in the Duchesne Municipal Airport Overlay District:

"Airport" means the Duchesne Municipal Airport.

"Airport elevation" means the highest point of the airport's usable landing area measured in feet above sea level. The Duchesne Municipal Airport is five thousand eight hundred thirty (5,830) feet above mean sea level.

"Airport-compatible land uses" means those land uses that can coexist with a nearby airport without constraining the safe and efficient operation of the airport or exposing people living or working nearby to potential negative environmental or safety impacts. Airport-compatible land uses do not create airspace obstructions and hazards to safe navigation (such as tall structures, light, glare, electronic/radio, smoke, steam, or other atmospheric interference emanating from nearby land uses). Airport-compatible land uses do not attract birds and other wildlife hazards to 3 the airport and its immediate environs and do not bring high concentrations of people within airport runway protection zones. Though it is not a land use authority, the entity authorized to determine what constitutes an airport-compatible land use, in terms of the impact on the airspace, is the FAA, via issuance of a Determination of No Hazard to Air Navigation or a finding that the applicant does not exceed the criteria of the FAA Notice Criteria tool. The City land use authority determines what constitutes an airport compatible land use, based on consultation with the City and guidance found in Advisory Circular 150/5 I 90-48 (or latest edition)(amd Ord 26-01, 01/27/2026)

"Approach surface" means an imaginary surface longitudinally centered on the extended runway centerline, extending outward and upward from the end of the primary surface and at the same slope as the approach zone height limitation slope set forth in Section 15.1.5 F below. The perimeter of the approach surface coincides with the perimeter of the approach zone in plan view.

"Approach, Transitional, Horizontal, and Conical Zones." These zones are defined in Section 15.1.5 E below.

"City" means the City of Duchesne, Utah.

"Conical surface" means an imaginary surface extending outward and upward from the periphery of the horizontal surface at a slope of twenty (20) to one (20:1) for a horizontal distance of four thousand (4,000) feet.

"County" means Duchesne County, Utah.

"FAA Form 7460-1, Notice of Proposed Construction or Alteration" means a form which the Federal Aviation Administration requires to be completed by anyone who is proposing to construct or alter an object that could affect airspace and allows the FAA to conduct an airspace analysis to determine whether the object will adversely affect airspace or navigational aids. More information regarding this requirement can be found on the FAA website.

"FAR Part 77 surfaces" means imaginary airspace surfaces, per Part 77 of 49 CFR of the Federal Aviation Regulations, established with relation to each runway of an airport. There are five types of surfaces: (1) primary; (2) approach; (3) transitional; (4) horizontal; and (5) conical.

"Hazard to air navigation" means an obstruction determined to have a substantial adverse effect on the safe and efficient utilization of the navigable airspace.

“High Density Residential” means residential development greater than four dwelling units per acre.

"Horizontal surface" means a horizontal plane one hundred fifty (150) feet above the established airport elevation, the perimeter of which surface coincides with the inner perimeter of the conical surface. (amd Ord 26-01, 01-27-2026)

"Low Density Residential" means residential development of one dwelling unit per acre or less.

"Obstruction" means any permanent or temporary structure, growth, or other object, including a mobile object, which exceeds a limiting height set forth in Section 15.1.5 F below.

"Person" means an individual, firm, partnership, corporation, company, association, joint stock association, or governmental entity, including a trustee, receiver, assignee, or similar representative of any of them. 4

"Primary surface" means a surface longitudinally centered on a runway. The primary surface has a width and distance beyond each end of the runway. The elevation of any point on the primary surface is the same as the elevation of the nearest point on the runway centerline. The primary surface at Duchesne Municipal Airport on runway 17/35, which is paved) is five hundred (500) feet wide and extends two hundred (200) feet beyond runway end. On runway 8/26, which is not paved, the primary surface is 250 feet wide and extends two hundred (200) feet beyond the end of the runway. (amd Ord 26-01, 01-27-2026)

"Runway" means a defined area on an airport prepared for landing and takeoff of aircraft along its length, at the Duchesne Municipal Airport.

"Structure" means an object (including a mobile object extending 15 feet or more above a roadway surface, 17 feet or more above a highway surface or 23 feet or more above a railroad surface) constructed or installed by persons, including, but not limited to buildings, towers, cranes, smokestacks, earth formations, and overhead transmission lines.

"Transitional surfaces" means those imaginary surfaces extending outward at ninety (90) degree angles to the runway centerline at a slope of seven feet horizontally for each foot vertically, from the sides of the primary and approach surfaces to where they intersect with the horizontal surfaces. (amd Ord 26-01, 01/27/2026)