§ 5.03 ZONES DEFINED.
   (A)   Horizontal zone. The land lying under a horizontal surface. The horizontal surface is 147 feet above the established airport elevation and the perimeter is constructed by swinging arcs of 10,000 feet radii from the center of each end of the primary surface of Runways 15, 33, 3 and 21 and connecting the adjacent arcs by lines tangent to those arcs. No structure or tree shall exceed 147 feet above the established airport elevation in the horizontal zone, as depicted on the Davenport Municipal Airport Height Zoning Map.
   (B)   Conical zone. The land lying under a conical surface. The conical surface extends outward and upward from the periphery of the horizontal surface at a slope of 20 to one for a horizontal distance of 4,000 feet. No structure or tree in the conical zone shall penetrate the conical surface, as depicted on the Davenport Municipal Airport Height Zoning Map.
   (C)   Approach zone. The land lying under an approach surface. The approach surface is longitudinally centered on the extended runway centerline and extends outward and upward from each end of the primary surface.
      (1)   The inner edge of the approach surface is:
         (a)   Five hundred feet wide for Runways 3 and 21; and
         (b)   One thousand feet wide for Runways 15 and 33.
      (2)   The outer edge of the approach surface is:
         (a)   Three thousand five hundred feet wide for Runways 3, 21 and 33; and
         (b)   Sixteen thousand feet wide for Runway 15.
      (3)   The approach surface extends for a horizontal distance of:
         (a)   Ten thousand feet at a slope of 34:1 for Runways 3, 21 and 33; and
         (b)   Ten thousand feet at a slope of 50:1 and then 40,000 feet at a slope of 40:1 for Runway 15. No structure or tree in the approach zone shall penetrate the approach surface to any runway, as depicted on the Davenport Municipal Airport Height Zoning Map.
   (D)   Transitional zone. The land lying under the transitional surface. The transitional surface extends outward and upward at right angles to the runway centerline and the runway centerline extended, at a slope of 7:1 from the sides of the primary surface and from the sides of the approach surfaces. The transitional surface begins at the side of and at the same elevation as the approach surfaces and extends upward and outward to the conical surface at a slope of 7:1; or, if outside the conical surface, it extends upward and outward a distance of 5,000 feet measured horizontally from the edge of the approach surface and at right angles to the runway centerline. No structure or tree in the transitional zone shall penetrate the transitional surface, as depicted on the Davenport Municipal Airport Height Zoning Map.