§ 25-2. Definitions.

As used in this article, unless the context otherwise requires, the following terms shall have the following meanings:

Airport. Frank Wiley Field (also known as the Miles City Airport).

Airport elevation. Two thousand six hundred twenty-eight feet above mean sea level.

Approach surface. A surface longitudinally centered on the extended runway centerline, extending outward and upward from the end of the primary surface and at the same slope as the approach zone height limitation slope set forth in section 25-4. In plan, the perimeter of the approach surface coincides with the perimeter of the approach zone.

Approach, transitional, horizontal, and conical zones. Those zones as described and set forth in section 25-3.

Board of adjustment. A board consisting of three members appointed by the city council as provided for in MCA 67-6-206.

Conical surface. A surface extending 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.

Hazard to air navigation. An obstruction determined to have a substantial adverse effect on the safe and efficient utilization of the navigable airspace.

Height. For the purpose of determining the height limits in all zones set forth in this article and shown on the zoning map, the datum shall be mean sea level elevation unless otherwise specified.

Horizontal surface. A horizontal plane 150 feet above the established airport elevation, the perimeter of which plane coincides with the perimeter of the horizontal zone.

Nonconforming use. Any preexisting structure, object of natural growth, or use of land which is inconsistent with the provisions of this article or amendment thereto.

Obstruction. Any structure, growth, or other object, including a mobile object, which exceeds a limiting height set forth in section 25-4.

Person. An individual, firm, partnership, corporation, company, association, joint stock association, or governmental entity; includes a trustee, a receiver, an assignee, or a similar representative of any of them.

Primary surface. A surface longitudinally centered on a runway. When the runway has a specially prepared hard surface, the primary surface extends 200 feet beyond each end of that runway; when the runway has no specially prepared hard surface, or planned hard surface, the primary surface ends at each end of that runway. The width of the primary surface is set forth in section 25-3. The elevation of any point on the primary surface is the same as the elevation of the nearest point on the runway centerline.

Runway. A defined area on an airport prepared for landing and takeoff of aircraft along its length.

Structure. An object, including a mobile object, constructed or installed by man, including but without limitation, buildings, towers, cranes, smokestacks, earth formation, or overhead transmission lines.

Transitional surfaces. These surfaces extend outward at 90-degree angles to the runway centerline and the runway centerline extended at a slope of seven feet horizontally for each foot vertically from the sides of the primary and approach surfaces to where they intersect the horizontal and conical surfaces.

Tree. Any object of natural growth.

Utility runway. A runway that is constructed for and intended to be used by propeller driven aircraft of 12,500 pounds of maximum gross weight and less.

Visual runway. A runway intended solely for the operation of aircraft using visual approach procedures.

(Ord. No. 1307 , § 1, 11-9-16)