Chapter 18.104
AIRPORT OBSTRUCTION OVERLAY ZONE, AO

Sections:

18.104.010    Purpose.

18.104.020    Airport zone height limitations.

18.104.030    Use restrictions.

18.104.040    Nonconforming uses.

18.104.050    Permits.

18.104.010 Purpose.

In order to carry out the provisions of this chapter, 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 county-city of Prineville Airport. Such zones are shown on the Prineville Airport approach and clear zone map contained in the county-Prineville Airport master plan ordinance and made a part hereof. 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 and defined as follows:

(1) Utility Runway Visual Approach Zone. The inner edge of this approach zone coincides with the width of the primary surface and is 250 feet wide for Runway 15/33. The approach zone expands outward uniformly to a width of 1,250 feet at a horizontal distance of 5,000 feet from the primary surface. Its center line is the continuation of the center line of the runway.

(2) Runway Larger Than Utility with a Visibility Minimum Greater Than Three-Quarter-Mile Nonprecision Instrument Approach Zone. The inner edge of this approach zone coincides with the width of the primary surface and is 500 feet wide for Runway 10/28. The approach zone expands outward uniformly to a width of 3,500 feet at a horizontal distance of 10,000 feet from the primary surface. Its center line is the continuation of the center line of the runway.

(3) Transitional Zones. The transitional zones are the areas beneath the transitional surfaces.

(4) Horizontal Zone. The horizontal zone is established by swinging arcs of 10,000-foot 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.

(5) Conical Zone. 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. (Ord. 18 § 3.210(1), 2003)

18.104.020 Airport zone height limitations.

Except as otherwise provided in this chapter, no structure shall be erected, altered, or maintained and no tree shall be allowed to grow in any zone created by this chapter to a height in excess of the applicable height limit herein established for such zone. Such applicable height limitations are hereby established for each of the zones in question as follows:

(1) Utility Runway Visual Approach Zones – Runway 15/33. Slopes 20 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 5,000 feet along the extended runway center line.

(2) Runway Larger Than Utility with a Visibility Minimum Greater Than Three-Quarter-Mile Nonprecision Instrument Approach Zone – Runway 10/28. 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 center line.

(3) Transitional Zones. 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 3,246 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 at the same elevation as the approach surface, and extending to where they intersect the conical surface.

(4) Horizontal Zone. Established at 150 feet above the airport elevation or at a height of 3,396 feet above mean sea level.

(5) Conical Zone. 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.

(6) Excepted Height Limitations. Nothing in this title shall be construed as prohibiting the construction or maintenance of any structure or growth of any tree to a height up to 35 feet above the surface of the land.

(7) Where an area is covered by more than one height limitation, the more restrictive limitation shall prevail. (Ord. 18 § 3.210(2), 2003)

18.104.030 Use restrictions.

Notwithstanding any other provisions of this chapter, no use may be made of land or water within any zone established by this chapter 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. (Ord. 18 § 3.210(3), 2003)

18.104.040 Nonconforming uses.

(1) Regulations Not Retroactive. The regulations prescribed by this chapter shall not be construed to require the removal, lowering, or other change or alteration of any structure or tree not conforming to the regulations as of the effective date of this chapter, or otherwise interfere with the continuance of nonconforming use. Nothing contained herein shall require any change in the construction, alteration, or intended use of any structure, the construction or alteration of which was begun prior to the effective date of the ordinance codified in this title, and is diligently prosecuted.

(2) Marking and Lighting. Notwithstanding the preceding provisions of this chapter, the owner of any existing nonconforming 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 airport owner 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 expense of the airport owner. (Ord. 18 § 3.210(4), 2003)

18.104.050 Permits.

(1) Future Uses. Except as specifically provided in subsections (1)(a), (b) and (c) of this section, no material change shall be made in the use of land, no structure shall be erected or otherwise established, and no tree shall be planted in any zone hereby created unless a permit therefor shall have been applied for and granted. Each application for a permit shall indicate the purpose for which the permit is desired, with sufficient particularity to permit it to be determined whether the resulting use, structure, or tree would conform to the regulations herein prescribed. If such determination is in the affirmative, the permit shall be granted. No permit for a use inconsistent with the provisions of this chapter shall be granted unless a variance has been approved in accordance with this chapter.

(a) In the area lying within the limits of the horizontal zone and conical zone, no permit shall be required for any tree or structure less than 75 feet of vertical height above the ground, except when, because of terrain, land contour, or topographic features, such tree or structure would extend above the height limits prescribed for such zones.

(b) In areas lying within the limits of the approach zones, but at a horizontal distance of not less than 4,200 feet from each end of the runway, no permit shall be required for any tree or structure less than 75 feet of vertical height above the ground, except when such tree or structure would extend above the height limits prescribed for such approach zones.

(c) In the areas lying within the limits of the transition zones beyond the horizontal zone, no permit shall be required for any tree or structure less than 75 feet of vertical height above the ground, except when such tree or structure, because of terrain, land contour, or topographic features, would extend above the height limit prescribed for such transition zones.

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 height limits established by this chapter except as set forth in this chapter.

(2) Existing Uses. No permit shall be granted that would allow the establishment or creation of an obstruction or permit a nonconforming use, structure, or tree to become a greater hazard to air navigation than it was on the effective date of the ordinance codified in this title or any amendments thereto or than it is when the application for a permit is made. Except as indicated, all applications for such a permit shall be granted.

(3) Nonconforming Uses Abandoned or Destroyed. Whenever the Crook County assessor determines that a nonconforming structure has been abandoned or more than 80 percent torn down or physically deteriorated, no permit shall be granted that would allow such structure to exceed the applicable height limit or otherwise deviate from the zoning regulations.

(4) Variances. Any person desiring to erect or increase the height of any structure, or permit the growth of any tree, or use property not in accordance with the regulations prescribed in this chapter may apply to the planning commission for a variance from such regulations. The application for variance shall be accompanied by a 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. 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 title. Additionally, no application for variance to the requirements of this title may be considered by the planning commission unless a copy of the application has been furnished to the airport owner for advice as to the aeronautical effects of the variance. If the airport owner does not respond to the application within 15 days after receipt, the planning commission may act on its own to grant or deny said application.

(5) Obstruction Marking and Lighting. Any permit or variance granted may, if such action is deemed advisable to effectuate the purpose of this title and be reasonable in 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 planning commission, this condition may be modified to require the owner to permit the airport owner, at his own expense, to install, operate, and maintain the necessary markings and lights. (Ord. 18 § 3.210(5), 2003)