The airport hazard overlay district, designated AH, is established to prevent the creation of airport hazards, thereby protecting the lives and property of users of the various county airports and the occupants of the land in the vicinity of the county airports. The board of supervisors finds it necessary to provide height and land use regulations in the vicinity of county airports to protect and promote the health, safety, and general welfare of the inhabitants of the county pursuant to the state law. The AH overlay zone district shall be in addition to the underlying zone district regulations with which it is established.

The provisions of this title have been revised to incorporate the "Policy Plan and Airport Comprehensive Land Use Plans" that were adopted by the Inyo County airport land use commission, in December 1991, pursuant to Section 21670 et seq. of the State of California Public Utilities Code.

Primary Surface. The primary surface is a surface longitudinally centered on the runway. When the runway has a specifically prepared hard surface, the primary surface extends two hundred feet beyond each end of the runway; but when the runway has no specially prepared hard surface, the primary surface ends at each end of that runway. The elevation of any point of the primary surface is the same as the elevation of the nearest point on the runway centerline. The width of the primary surface is two hundred fifty feet for all runways at all airports except for the nonprecision runways at Bishop and Lone Pine Airports where the width is five hundred feet.

Approach Surface. The approach surface is a 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. The inner edge of the approach surface is the same width as the primary surface and it expands uniformly to a width of one thousand two hundred fifty feet, at five thousand feet in length with an approach slope of 20:1, for that end of all runways at all public use airports in Inyo County except for those nonprecision instrument runways at Bishop and Lone Pine Airports where the approach surface expands uniformly, from the primary surface, to a width of three thousand five hundred feet, at ten thousand feet in length with an approach slope of 34:1.

Transition Surface. These surfaces extend outward and upward at right angles to the runway center line and the runway centerline extended at a slope of 7:1 from the sides of the primary surfaces. 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 five thousand feet measured horizontally from the edge of the approach surface and at right angles to the runway centerline.

Horizontal Surface. The horizontal surface is a horizontal plane one hundred fifty feet above the established airport elevation, the perimeter of which is constructed by swinging arcs of a specified radii from the center of each end of the primary surface of each runway and connecting the adjacent arcs by lines tangent to those arcs. The radius of each arc is five thousand feet for all runways in Inyo County except for those nonprecision runways at Bishop and Lone Pine Airports where the radius of each arc is ten thousand feet.

Conical Surface. The conical surface is 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.

Runway Protection Zone. The runway protection zone is the land area which lies under the approach surface from the end of the primary surface for a distance of one thousand feet for all runways at all public use airports in Inyo County except for those nonprecision runways at Bishop and Lone Pine Airports where the distance is one thousand seven hundred feet.

Bishop Airport;

Independence Airport;

Lone Pine Airport;

Shoshone Airport;

Trona Airport;

Death Valley National Monument Airport (Furnace Creek);

Death Valley, Stovepipe Wells Airport.

Before that portion of any nonconforming structure which exceeds height limitations established by this chapter may be structurally altered and before any nonconforming structure or natural growth may be replaced, reconstructed, allowed to grow higher or replanted, a conditional use permit must be approved by the planning commission authorizing such structural alteration, replacement, reconstruction or change. Those portions of an existing nonconforming structure or natural growth below the height limitations established in this chapter shall not be affected by the provisions of this chapter. Minor repair or alteration of nonconforming structures pursuant to Section 18.78.270 shall not require a conditional use permit provided the repair or alteration does not exceed the applicable height limitations.

Pursuant to Section 18.62.050, no structure or man-made or natural object shall be permitted to exceed the established height limits of the AH zone surfaces without first securing a conditional use permit from the county planning commission. Except as otherwise provided in this chapter, the conditional use permit process and procedure shall be that contained in Section 18.81.100 et seq.

Pursuant to Section 18.62.060, no structure may be erected in the runway protection zone or use made of land lying within any portion of the approach surface which would result in a concentration of people without first securing a conditional use permit from the county planning commission. Except as otherwise provided in this chapter, the conditional use permit process and procedure shall be that contained in Section 18.81.100 et seq.

Issuance of any use or conditional use permit for development of any land use whatsoever, located within any area defined within Section 18.62.020, and as shown on the zoning maps, shall be subject to the grant of an aviation easement to the county.

In all cases where a conditional use permit is required pursuant to this chapter to permit a structure, man-made or natural object to exceed the height limitations established in this chapter, the applicant shall be referred to the Federal Aviation Administration for their review pursuant to the requirements of Part 77 of the Federal Aviation Regulations. The conditional use permit application shall include a copy of the Federal Aviation Administration's findings, conclusions and conditions pursuant to the Part 77 review and this chapter. No action shall be taken by the county until evidence has been produced indicating the Federal Aviation Administration's Part 77 review requirements have been satisfied.

In all other cases where a conditional use permit is required pursuant to this chapter, the planning commission may, at its own discretion, refer the project to the Federal Aviation Administration and the California State Division of Aeronautics for their review and comment prior to action by the planning commission.