§ 156.137  AIRPORT OVERLAY.
   (A)   Intent. It is the intent of these requirements to restrain influences which are adverse to the property and safe conduct of airport operations in the vicinity of Wilkes County Airport, to prevent creation of conditions hazardous to aircraft operation, to prevent conflict with land development which may result in loss of life and property, and to encourage development that is compatible with airport use characteristics within the intent and purpose of zoning.
   (B)   Airport height limitation zones. In order to carry out the provisions of this section, there are hereby created and established certain zones which include all of the land lying beneath the approach surfaces, transitional surfaces, horizontal surfaces, and conical surfaces as they apply to the Airport.  Such zones are shown on the Official Zoning Map.  An area located in more than one of the following zones is considered to be only in the zone with the more restrictive height limitation.  The various zones are hereby established as subclassifications of the Airport Overlay District and are defined as follows:
      (1)   Precision Instrument Runway Approach Zone (AO-A1). The inner edge of this approach zone coincides with the width of the primary surface and is 1,000 feet wide.  The approach zone expands outward uniformly to a width of 16,000 feet at a horizontal distance of 50,000 feet from the primary surface.  Its centerline is the continuation of the centerline of the runway.
      (2)   Runway Larger than Utility Visual Approach Surface (AO-A2). The inner edge of this surface begins at and corresponds with the width of the primary surface and is 1,000 feet wide.  This surface rises uniformly at a 20:1 slope to a width of 1,500 feet at a horizontal distance of 5,000 feet from the primary surface along the extended runway centerline.
      (3)   Runway Larger than Utility with a Visibility Minimum as Low as ¾ Mile Nonprecision Instrument Approach Zone (AO-A3). The inner edge of this approach zone coincides with the width of the primary surface and is 1,000 feet wide.  The approach zone expands outward uniformly to a width of 4,000 feet at a horizontal distance of 10,000 feet from the primary surface.  Its centerline is the continuation of the centerline of the runway.
      (4)   Transitional Zone (AO-T). The transitional zones are the areas beneath the transitional surfaces.
      (5)   Horizontal Zone (AO-H). The horizontal zone is established by swinging arcs of 10,000 feet radii from the center of each end of the primary surface of each runway and connecting the adjacent arcs by drawing lines tangent to those arcs.  The horizontal zone does not include the approach and transitional zones.
      (6)   Conical Zone (AO-C). The conical zone is established as the area that commences at the periphery of the horizontal zone and extends outward therefrom a horizontal distance of 4,000 feet.
   (C)   Airport environs height limitations. Except as otherwise provided in this section, no structure shall be erected, altered, or maintained, and no tree shall be allowed to grow in any zone created under this section to a height in excess of the applicable height herein established for such zone.  Such applicable height limitations are hereby established for each of the zones in question as follows:
      (1)   Precision Instrument Runway Approach Zone (AO-A1). Slopes 50 feet outward for each foot upward beginning at the end of and at the same elevation as the primary surface and extending to a horizontal distance of 10,000 feet along the extended runway centerline; thence slopes upward 40 feet horizontally for each foot vertically to an additional horizontal distance of 40,000 feet along the extended runway centerline.
      (2)   Runway Larger than Utility Visual Approach Surface (AO-A2).  The inner edge of this surface begins at and corresponds with the width of the primary surface and is 1,000 feet wide.  This surface rises uniformly at a 20:1 slope to a width of 1,500 feet at a horizontal distance of 5,000 feet from the primary surface along the extended runway centerline.
      (3)   Runway Larger than Utility with a Visibility Minimum as Low as ¾ Mile Nonprecision Instrument Approach Zone (AO-A3). Slopes 34 feet outward for each foot upward beginning at the end of and at the same elevation as the primary surface and extending to a horizontal distance of 10,000 feet along the extended runway centerline.
      (4)   Transitional Zone (AO-T). Slopes seven feet outward for each foot upward beginning at the sides of and at the same elevation as the primary surface and the approach surface, and extending to a height of 150 feet above the Airport elevation which is 1,301 feet above mean sea level.  In addition to the foregoing, there are established height limits sloping seven feet outward for each foot upward beginning at the sides of and the same elevation as the approach surface, and extending to where they intersect the conical surface.  Where the precision instrument runway approach zone projects beyond the conical zone, there are established height limits sloping seven feet outward for each foot upward beginning at the sides of and the same elevation as the approach surface and extending a horizontal distance of 5,000 feet measured at 90 degree angles to the extended runway centerline from the edge of the approach surface.
      (5)   Horizontal Zone (AO-H). Established at a height of 150 feet above the Airport elevation or an elevation of 1,451 feet above mean sea level.
      (6)   Conical Zone (AO-C). Slopes 20 feet outward for each foot upward beginning at the periphery of the horizontal zone and at 150 feet above the Airport elevation and extending to a height of 350 feet above the Airport elevation, or an elevation of 1,651 feet above mean sea level.
      (7)   Expected height limitations. Nothing in this section shall be construed as prohibiting the erection, alteration, or maintenance of any structure or growth of any tree at or to a height which is below the limitations set forth herein.
   (D)   Regulation related to sanitary landfill location. Due to the increased attraction of birds in the vicinity of sanitary landfills and the potential hazards which birds create to aircraft operations (see FAA Order SO 5200.5), the following provisions shall apply:
      (1)   No sanitary landfill shall be located within 10,000 feet from a runway of any airport.
      (2)   Sanitary landfills which are proposed to be located further than 10,000 feet from a runway of any airport but within the conical surface will be reviewed on a case by case basis by the Town Board, which may in turn consult with the FAA.  If, in the opinion of the Town Board or the FAA, the proposed landfill poses a threat to safe aircraft operations, then the landfill shall not be allowed in the proposed location.
   (E)   Use restriction. Notwithstanding any other provision of this section, no use may be made of land or water within any zone established hereunder in such a manner as to create electrical interference with navigational signals or radio communication between the airport and aircraft, make it difficult for pilots to distinguish between Airport lights and others, result in glare in the eyes of pilots using the airport, impair visibility in the vicinity of the airport, create bird strike hazards, or otherwise in any way endanger or interfere with the landing, takeoff, or maneuvering of aircraft intending to use the airport.
   (F)   Legal nonconformities. The owner of any existing non-conforming structure or tree is hereby required to permit the installation, operation, and maintenance thereon of such markers and lights as shall be deemed necessary by the town to indicate to the operators of aircraft in the vicinity of the airport the presence of such airport obstruction.  Such markers and lights shall be installed, operated, and maintained at the town's expense.
   (G)   Permits and variances.
      (1)   No permit shall be issued with respect to any use within this overlay district unless said use complies with all of the requirements of this section provided, however, that:
         (a)   In the area lying within the limits of the horizontal zone and conical zone, no permit shall be required for any use or structure except in cases where, because of terrain, land contour, or topographic features, such use or structure would extend above the height limits prescribed for such zones;
         (b)   In areas lying within the limits of the approach zones, no permit shall be required for any use or structure except in cases where such use or structure would extend above the height limit prescribed for such approach zones;
         (c)   In the areas lying within the limits of the transition zones beyond the perimeter of the horizontal zone, no permit shall be required for any use or structure except when such use or structure, because of terrain, land contour, or topographic features, would extend above the height limit prescribed for such transition zones; and
         (d)   Nothing contained in any of the foregoing exceptions shall be construed as permitting or intending to permit any construction, or alteration of any structure, or growth of any tree, in excess of any of the height limits established in § 156.138 Gateway Overlay (reserved for future use).
      (2)   Any application for a variance with respect to any use within this overlay district shall be accompanied by a written determination from the Federal Aviation Administration as to the effect of the proposal on the operation of air navigation facilities and the safe, efficient use of navigable airspace and the airport.  Such variances shall be allowed where it is duly found that a literal application or enforcement of the regulations will result in unnecessary hardship and relief granted will not be contrary to the public interest, will not create a hazard to air navigation, will do substantial justice, and will be in accordance with the spirit of this section.  Additionally, no application for variance to the requirements of this section may be considered by the Board of Adjustment unless a copy of the application has been furnished to the airport manager and the Wilkes County Airport Board for advice as to the aeronautical effects of the variance.  If the airport manager and/or the Airport Board does not respond to the application within 30 days after receipt, the Board of Adjustment may act on its own to grant or deny said application.
      (3)   Obstruction marking and lighting. Any permit or variance granted may, if such action is deemed advisable to effectuate the purpose of this section, and is reasonable under the circumstances, be so conditioned as to require the owner of the structure or tree in question to install, operate, and maintain, at the owner's expense, such markings and lights as may be necessary.  If deemed proper by the Board of Adjustment, this condition may be modified to require the owner to permit the Town of Wilkesboro, at its own expense, to install, operate, and maintain the necessary markings and lights.
(Am. Ord. passed 9-14-2016)