17.45.020 Types of zones and height limits.
Six types of AA subzones, and height limits for such subzones, are established for the purposes of airport approach zoning. Except as otherwise provided in this chapter, no structure or tree, shrub or bush shall be erected, altered, allowed to grow or be maintained in any subzone to a height in excess of the height limit established for such subzone. The datum plan for measurement of such height, except as otherwise specified herein, shall be based on the airport elevation, as defined by subsection B of Section 17.45.012. Appropriate subzones for heliports shall be established in accordance with Federal Aviation Regulations Part 77. Such subzones are as follows:
A. Landing Subzone (L). A surface, and the airspace above it, rectangular in shape, longitudinally centered on the runway and extending in length two hundred feet beyond the ends of the runway; the landing subzone shall have an elevation, at any point along its longitudinal profile, coincident with the runway centerline or centerline prolongations as appropriate; the landing subzone shall have width established in accordance with Federal Aviation Regulations Part 77 and shall be specified on each map adopted pursuant to Section 17.45.030.
B. Final Approach Subzone (FA). A plane surface, and the airspace above it, trapezoidal in shape, longitudinally centered on the prolongation of the runway centerline, beginning at each end of each landing subzone, coinciding in width with the landing subzone where they join; the height and width of the final approach subzone shall be established in accordance with Federal Aviation Regulations Part 77 and shall be specified on each map adopted pursuant to Section 17.45.030.
C. Landing Transition Subzone (LT). A plane surface, and the airspace above it, rectangular in shape, lying adjacent and parallel to each side of each landing subzone, having a length equal to the landing subzone and extending outward and upward, at right angles to the runway centerline, at a slope of seven-to-one to a height of one hundred fifty feet above the established airport elevation.
D. Approach Transition Subzone (AT). A plane surface and the airspace above it, triangular in shape, lying adjacent to each side of each approach zone and at each end of each landing transition subzone, coinciding in height with the approach outward and upward, at right angles to the prolongation of the runway centerline, at a slope of seven-to-one to a maximum airport elevation or to the conical subzone surface, whichever is higher.
E. Horizontal Subzone (H). A horizontal plane surface, and the airspace above it, one hundred fifty feet above the established airport elevation, the perimeter of which is constructed by swinging arcs of specific radii, established in accordance with Federal Aviation Regulations Part 77, from the center of each end of the landing subzone of each runway and connecting the arcs by lines tangent to such arcs; the horizontal subzone does not include the landing subzone or transition subzones.
F. Conical Subzone (C). A surface extending outward and upward from the periphery of the horizontal surface at a slope of 20:1 for a horizontal distance of four thousand feet. The conical subzone does not include the final approach subzone at the approach transition subzone. (Ord. 2719 § 1, 1982)