In order to carry out the provisions of this section, there are hereby created and established certain zones which are depicted on the Knoxville Municipal Airport Height Zoning Map. A structure located in more than one (1) 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 land lying under a horizontal plane one hundred fifty (150) feet above the established elevation, the perimeter of which is constructed by swinging arcs of five thousand (5,000) feet radii from the center of each end of the primary surface of runways 15, 33, 5 and 23, and connecting the adjacent arcs by lines tangent to those arcs. No structure shall exceed one hundred and fifty (150) feet above the established airport elevation in the horizontal zone, as depicted on the Knoxville Municipal Airport Height Zoning Map.
2. Conical Zone. The land lying under a surface extending outward and upward from the periphery of the horizontal surface at a slope of twenty (20) to one (1) for a horizontal distance of four thousand (4,000) feet. No structure shall penetrate the conical surface in the conical zone, as depicted on the Knoxville Municipal Airport Height Zoning Map.
3. Approach Zone. The land lying under a surface longitudinally centered on the extended runway centerline and extending outward and upward from each end of the primary surface.
(Note: 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 500 feet wide for runways 15 and 33 and 250 feet for runways 5 and 23.
B. The outer edge of the approach zone is 2,000 feet for runways 15 and 33 and 1,250 feet for runways 5 and 23.
C. The approach zone extends for a horizontal distance of 5,000 feet at a slope of twenty (20) to one (1) for runways 15, 33, 5 and 23.
No structure shall exceed the approach surface to any runway, as depicted on the Knoxville Municipal Airport Height Zoning Map.
4. Transitional Zone. 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 (7) to one (1) from the sides of the primary surface and from the sides of the approach surfaces. No structure shall exceed the transitional surface, as depicted on the Knoxville Municipal Airport Height Zoning Map.
5. Increase in Elevation of Structures. No structure shall be erected in Marion 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.