§ 151.02 DEFINITIONS. — Eureka Zoning Code

For the purpose of this chapter, the following definitions shall apply unless the context clearly indicates or requires a different meaning.

AIRPORT. Any publicly owned or publicly administered airport located within the city.

AIRPORT APPROACH ZONE. The approach area and the air space directly above it.

AIRPORT HAZARD. Any structure, tree, or use of land which obstructs the air space required for the flight of aircraft in landing or taking off from any airport or which is otherwise hazardous to such landing or taking off of aircraft.

AIRPORT HAZARD AREA. Any area of land or water upon which an airport hazard might be established if not prevented as provided in this chapter. The zones described in this section are hereby designated as the airport hazard areas of all airports subject to the provisions of this chapter.

AIRPORT REFERENCE POINT. A point selected and marked at the approximate center of the airport landing area. AIRPORT TRANSITION ZONE. The land area directly beneath the transition surfaces and the air spaces directly above and below the transition surfaces.

AIRPORT TURNING ZONE. The land areas directly beneath the conical surface and the horizontal surface and the air spaces directly above and below the horizontal surface and the conical surface.

APPROACH AREA LENGTH. The approach area has a length of 10,000 feet beginning 200 feet outward from the end of each runway and extended outward, ending at a point 10,200 feet from the end of the runway on the extended center line of the runway. In addition, the approach areas of all runways which are used for instrument operation shall extend outward an additional 40,000 feet. The approach area requirements for instrument runways shall apply to all runways which are used for instrument operations and to both ends of such runways.

APPROACH AREA SLOPE. For instrument runways the slope of the approach surface along the runway center line extended is 50:1 for the inner 10,000 foot section and 40:1 for the outer 40,000 foot section. For all other runways, not intended for instrument operation, which meet or exceed the minimum runway length requirements for feeder carrier service, the slope is 40:1. On airports with shorter runway lengths than those specified for feeder air carrier service, the slope of the approach surface is 20:1 for all runways.

APPROACH AREA WIDTH. The approach area is symmetrically located with respect to the extended runway center line and for all instrument runways has a total width of 1,000 feet at the end adjacent to the runway. The approach area flares uniformly to a total width of 4,000 feet at the end of the 10,000-foot section and to a total width of 16,000 feet at the end of the additional 40,000foot section. For all other runways not intended for instrument operation, the approach area has a total width at the end adjacent of the runway and at the approach respectively as follows:

(1) For express air carrier service and larger airports, 500 feet and 2,500 feet;
(2) For trunk line air carrier service airports, 400 feet and 2,400 feet;
(3) For feeder air carrier service airports, 300 feet and 2,300 feet; and,
(4) For secondary airports, 250 feet and 2,250 feet.

APPROACH SURFACES. Inclined planes located directly above the approach area. The dimensions of the approach shall be measured horizontally.

CONICAL SURFACE. The conical surface extends upward and outward from the periphery of the horizontal surface with a slope of 20:1 measured in a vertical plan passing through the airport reference point. Measuring radially outward, from the periphery of the horizontal surface, the conical surface extends for a horizontal distance of 7,000 feet for intercontinental airports and intercontinental express airports; 5,000 feet for continental, express, trunk line, and feeder airports; and 3,000 feet for all smaller airports.

ESTABLISHED ELEVATION OF AN AIRPORT. The elevation of the highest point of the usable landing area. HORIZONTAL SURFACE. The horizontal surface is a plane, circular in shape, with its height 150 feet above the established

airport elevation and having a radius from the airport reference point as indicated in the following table, which table also indicates the classification of each airport for the purposes of this chapter:

(1) Intercontinental express airports, 13,000 feet.
(2) Intercontinental airports (Arcata Airport), 11,500 feet.
(3) Continental airports, 10,000 feet.
(4) Express airports, 8,500 feet.
(5) Trunk line airports, 7,000 feet.
(6) Feeder airports (Rohnerville Airport), 6,000 feet.
(7) Secondary airports (Eureka County Airport, Eureka Municipal Airport, Garberville Airport, Shelter Cove Airport, and Dinsmore Airport), 5,000 feet.

LANDING AREA. The area of an airport used for landing, taking off, or taxiing of aircraft, consisting of the areas more particularly described in other sections of this chapter.

NONCONFORMING USE. Any structure, tree, or use of land which does not conform to a regulation prescribed in this chapter on June 21, 1956.

STRUCTURE. Any object constructed or installed by man, including, but without limitations, buildings, towers, smokestacks, mill burners, and overhead transmission lines.

TRANSITIONAL SURFACES. The transitional surfaces and inclined planes with a slope of 7:1 measured upward and outward

in a vertical plane at right angles to the center line of the runway. The transitional surfaces, symmetrically located on either side of the runway, extend upward and outward from a line on either side of the runway which is parallel to and level with the runway center line. Such parallel lines are at a horizontal distance from the runway center line equal to one-half the minimum width of the approach area. Transitional surfaces extend from the edges of all approach surfaces upward and outward to the intersection with the horizontal surface or conical surface. The approach surfaces for instrument runways projecting through and beyond the limits of the conical surface have a 7:1 transitional surface extending a distance of 5,000 feet measured horizontally from the edge of the approach surfaces and at right angles to the runway center line.

TREE. Any object of natural growth.

('63 Code, § 10-1.02) (Ord. 2660, passed 6-19-56)