17.95.020 Definitions.
For the purpose of this Chapter the following words and phrases shall have the following meanings:
(1) Airport. The Pullman-Moscow Regional Airport.
(2) Airport Elevation. The highest point of the airport’s usable landing area [2,551 feet above mean sea level (MSL)].
(3) Airport Hazard. Any structure, tree, or mobile object located at, or moving through the airport or its vicinity, or any use of land near the airport that obstructs the navigable airspace required for the flight of aircraft.
(4) Airport Imaginary Surfaces. The following airport imaginary surfaces are established with relation to the airport and its runway. The size of each imaginary surface is based on the type of approach available or planned for each end of the runway. The slope and dimensions of the approach surface applied to each end of the runway are determined by the most precise approach existing or planned for that end of the runway.
(a) Horizontal Surface. A horizontal plane one hundred fifty (150) feet above the airport elevation, the perimeter of which is constructed by swinging arcs of 10,000 feet radii from the center of each end of the primary surface of the runway and connecting the adjacent arcs with lines tangent to them.
(b) Conical Surface. A surface extending upward and outward from the periphery of the horizontal surface at a slope of 20:1 (run to rise) for a horizontal distance of 4,000 feet.
(c) Primary Surface. A five hundred (500) foot wide surface longitudinally centered on and extending two hundred (200) feet beyond each end of the runway. The elevation of any point on the primary surface is the same as that of the nearest point on the runway centerline.
(d) Approach Surface. A surface longitudinally centered on the extended runway centerline and extending outward and upward from each end of the primary surface. At the Pullman-Moscow Regional Airport, there are two (2) approach surfaces, the inner edge of which begins at and is the same width and elevation as the primary surface.
(i) The larger than utility runway visual approach surface expands uniformly outward to a width of 1,500 feet and upward at a slope of 20:1 (run to rise) to a horizontal distance of 5,000 feet beyond the end of the primary surface.
(ii) The larger than utility runway with a visibility minimum greater than 3/4 mile nonprecision instrument approach surface expands uniformly outward to a width of 3,500 feet and upward at a slope of 34:1 (run to rise) to a horizontal distance 10,000 feet beyond the end of the primary surface.
(e) Transitional Surface. A surface extending outward and upward at right angles to the runway centerline and the runway centerline extended at a slope of 7:1 (run to rise) from the sides of the primary surface and from the sides of the approach surfaces to where they intersect the horizontal surface.
(5) Height. For the purposes of determining the height limits in the Airport Height Limitation Overlay Districts, the base datum shall be mean sea level, unless otherwise specified.
(6) Larger than Utility Runway. Any runway constructed and intended for use by propeller-driven aircraft of greater than 12,500 pounds maximum gross weight, or by jet aircraft.
(7) Nonprecision Instrument Runway. Any runway having an existing instrument approach procedure that utilizes air navigation facilities with only horizontal guidance, or area type navigation equipment, for which a straight-in nonprecision instrument approach has been approved or planned.
(8) Obstruction. Any structure or tree that exceeds the height limits established in 17.95.040 of this Chapter.
(9) Runway. Refers to Runway 5-23 at the Pullman-Moscow Regional Airport.
(10) Structure. Any object, including a mobile object, constructed or installed by man, including buildings, towers, cranes, smoke stacks, earth formations, and overhead transmission lines.
(11) Substantial Noise Impact Area. All areas where the existing or potential airport-related noise levels exceed 65 Ldn (day-night average).
(12) Tree. Any object of natural growth. (Ord. 87-9 §1, 1987).