§ 157.13  HEIGHT LIMITATIONS.
   (A)   No structure, object, natural vegetation, or terrain shall be erected, altered, allowed to grow or be maintained within any airport zoning district established by this ordinance to a height in excess of the applicable height limitations set forth in this ordinance.  The permitted height shall not exceed the difference between the grade elevation and the height limitation numbers illustrated on the "Official Clinton Municipal Airport Height Overlay Map" within the various airport zoning districts encompassed by this ordinance.  The Clinton Municipal Airport Height Overlay Map is located in the Airport Manager’s office.
   (B)   An FAA 7460-1 airspace review shall provide a portion of the information necessary to evaluate potential height impacts.  However, it shall not be the sole source of review.
   (C)   In order to carry out the provisions of this chapter, there are hereby created and established certain zones which are depicted on the municipal airport height zoning map. A structure located in more than one zone of the following zones is considered to be only in the zone with the more restrictive height limitations. The various zones are hereby established and defined as follows.
      (1)   Horizontal zone. The horizontal zone is the land lying under a horizontal plane 150 feet above the established airport elevation, the perimeter of which is constructed by:
         (a)    Swinging arcs of 10,000 feet radii from the center of each end of the primary surface of runways 14 and 32 and connecting the adjacent arcs by lines tangent to those arcs;
         (b)    1.   Swinging arcs of 10,000 feet radii from the center of each end of the primary surface of runways 3 and 21, and connecting the adjacent arcs by lines tangent to those arcs; and
            2.   No structure shall exceed 150 feet above the established airport elevation in the horizontal zone, as depicted on the municipal airport height zoning map.
      (2)   Conical zone. The conical zone is the land lying under a surface extending outward and upward from the periphery of the horizontal surface at a slope of 20 feet to one for a horizontal distance of 4,000 feet. No structure shall penetrate the conical surface in the conical zone, as depicted on the municipal airport height zoning map.
      (3)   Approach zone. The approach zone is the land lying under the surface longitudinally centered on the extended runway centerline and extending outward and upward from each end of the primary surface.  An approach surface is applied to each end of each runway based upon the type of approach available or planned for that runway end.
         (a)   The inner edge of the approach surface is:
            1.   Five hundred feet wide for runways 14, 21, and 32. (Visual other than utility runway and nonprecision instrument runway); and
            2.   1,000 feet wide for runway 3 (precision instrument runway).
         (b)   The outer edge of the approach zone is:
            1.   3,500 feet for runway 32 (visual other than utility runways);
            2.   3,500 feet for runway 14 (nonprecision instrument utility runways);
            3.   3,500 for runway 21 (nonprecision instrument utility runways); and
            4.   16,000 thousand feet for runway 3 (precision instrument runways).
         (c)   The approach zone extends for a horizontal distance of:
            1.   10,000 feet at a slope of 34 to 1 for runways 14 and 32 (all visual and nonprecision instrument utility runways);
            2.   10,000 feet at a slope of 34 to 1 for runway 21 (nonprecision instrument other than utility runways);
            3.   A.   10,000 feet at a slope of 50 to 1, and then 12,000 feet at a slope of 40 to 1, and then restricted to 500 feet above airport elevation for 28,000 feet for runway 3 (precision instrument runways); and
               B.   No structure shall exceed the approach surface to any runway, as depicted on the municipal airport height zoning map.
      (4)   Transitional zone. The transitional zone is the land lying under those surfaces extending outward and upward at right angles to the runway centerline and the runway centerline extended at a slope of seven to one from the sides of the primary surface and from the sides of the approach surfaces. The transitional surfaces extend to the point at which they intercept the horizontal surface at a height of 150 feet above the established airport elevation.  Transitional surfaces for those portions of the precision approach surface which project through and beyond the limits of the conical surface, extend a distance of 5,000 feet measured horizontally from the edge of the approach surface and at right angles to the runway centerline. The transitional surface for the precision approach extends upward and outward at a slope of seven to one until it intersects a place 500 feet above the airport elevation, at which time it becomes a plane 500 feet above airport elevation. No structures shall exceed the transitional surface, as depicted on the municipal airport height zoning map.
      (5)   Structural height limitations. No structure shall be erected in Clinton County or Scott County (together referred to in this chapter as "the county") that raises the published minimum descent altitude for an instrument approach to any runway, nor shall any structure be erected that causes the minimum obstruction clearance altitude or minimum en route altitude to be increased on any federal airway in the county.
(Ord. 2517, passed 2-24-2015)  Penalty, see § 157.99