A. Intent: These zones are intended to prevent the creation or establishment of airport hazards by regulating and restricting the height of structures and objects of natural growth in the vicinity of the airport.
B. Zones: Certain zones are established which include all of the land lying within the primary zones, horizontal zone, conical zone, precision instrument approach zones, nonprecision instrument (NPI) approach zones, visual approach zones, transition zones and critical area. Where both an existing and future threshold are planned for a runway, the approach zones will consist of the area enclosed by trapezoids for each threshold plus the lines connecting corresponding outboard corners of the two (2) trapezoids. Such areas and zones are shown in subsection 13-13-10B, airport airspace zones, of this chapter, for the airport, consisting of one sheet prepared by the airport board and dated January 2004, a copy of which is made a part hereof by reference. The various zones are defined and described as follows:
1. Primary Zones: Primary zones are hereby established as the area extending equidistantly on either side of each runway centerline with total width:
a. For utility visual runways, two hundred fifty feet (250').
b. For utility NPI, visual, and NPI (>3/4 mile approach visibility minimums) runways, five hundred feet (500').
c. For precision and NPI (3/4 mile approach visibility minimums) runways, one thousand feet (1,000').
For the length of such runway plus two hundred feet (200') on each end. (Except turf runways where the length equals the length of the runway.)
2. Horizontal Zone: A horizontal zone is hereby established as the area within a perimeter established by swinging arcs from points two hundred feet (200') beyond the existing or planned ends of the runways on the extended runway centerline, then connecting the adjacent arcs by lines tangent to those arcs. (For turf runways, the arcs begin at the runway ends.) When an arc is encompassed by tangents connecting two (2) adjacent arcs, the arc encompassed must be disregarded in delineating the perimeter of the horizontal surface. The radius of each arc is:
a. For all visual and utility runways, five thousand feet (5,000').
b. For all others, ten thousand feet (10,000').
The horizontal zone does not include the primary, approach, and transition zones.
3. Conical Zone: A conical zone is hereby established as the area that commences at the periphery of the horizontal zone and extends outward for a distance of four thousand feet (4,000'). The conical zone does not include the approach and transition zones.
4. Utility Nonprecision Instrument Approach Zones: A utility nonprecision instrument (NPI) approach zone is established at each end of utility nonprecision instrument runways. Each utility NPI approach zone shall have a width of five hundred feet (500') at a distance of two hundred feet (200') beyond each end of the runway, widening thereafter uniformly to a width of two thousand feet (2,000') at a distance of five thousand two hundred feet (5,200') beyond each end of the runway with its centerline being the continuation of the centerline of the runway. (Shelby runway 11-29 has a future utility NPI runway designation planned, with anticipated 1 mile approach visibility minimums.)
5. Nonprecision Instrument Approach Zones (1 Mile Approach Visibility Minimums): A nonprecision instrument (NPI) approach zone is established at each end of nonprecision instrument (NPI) runways. Each NPI approach zone shall have a width of five hundred feet (500') at a distance of two hundred feet (200') beyond each end of the runway, widening thereafter uniformly to a width of three thousand five hundred feet (3,500') at a distance of ten thousand two hundred feet (10,200') beyond each end of the runway with its centerline being the continuation of the centerline of the runway. (Runway 5-23 has a future NPI runway designation planned, with anticipated 1 mile approach visibility minimums.)
6. Transition Zones: Transition zones are hereby established adjacent to each approach zone and symmetrically located on each side of primary zones having variable widths as shown in subsection 13-13-10B, airport airspace zones, of this chapter. For precision instrument approach runways, an additional transitional zone is established exterior of the conical surface, extending a distance of five thousand feet (5,000') measured at right angles to the exterior of the conical surface.
C. Height Limitations: Except as otherwise provided in this chapter, no structure or tree shall be erected, altered, allowed to grow, or maintained in any zone created by this chapter to a height in excess of the height limitation established for such zone. Such height limitations are established for each of the zones as follows:
1. Primary Zones:
a. Objects greater than three inches (3") above grade shall be allowed only when constructed on low impact resistant supports with the frangible point no higher than three inches (3") above grade.
b. Objects that need to be located in this area because of their function shall be constructed at the lowest practical height.
2. Horizontal Zone: One hundred fifty feet (150') above the airport elevation.
3. Conical Zone: One hundred fifty feet (150') above the airport elevation plus one foot (1') in height for each twenty feet (20') of horizontal distance measured from and normal to the periphery of the horizontal zone.
4. Utility Nonprecision Instrument Approach Zones: For each runway end, the elevation of the threshold centerline plus one foot (1') in height for each twenty feet (20') measured perpendicularly from the end of the primary zone, extending five thousand feet (5,000').
5. Nonprecision Instrument Approach Zones: For each runway end, the elevation of the threshold centerline plus one foot (1') in height for each thirty four feet (34') measured perpendicularly from the end of the primary zone, extending ten thousand feet (10,000').
6. Transition Zones: Begin at an elevation equal to the elevation of the nearest point on the runway centerline, and extend outward and upward at right angles to the runway centerline or extended runway centerline, increasing one foot (1') in height for each seven feet (7') from the sides of the primary zone and from the sides of all approach zones.
7. Airport Critical Area: The area as called out in airport airspace zones, subsection 13-13-10B of this chapter, consisting of a fifty foot (50') elevation line, above the airport elevation, on all approach and transition zones.
D. Conflicting Regulations: When an area is covered by more than one height limitation, the more restrictive shall prevail.
E. Minimum Review Height: Nothing in this chapter shall be construed as prohibiting the growth, construction or maintenance of any tree or structure to a height:
1. Equal to or below the airport elevation.
2. Up to fifty feet (50') above the surface of the land except the area delineated as "airport critical area", subsection 13-13-10B of this chapter. (Ord. 766, 2-16-2004)