Definitions. The following words and phrases when used in this section shall have the meaning given to them in this section unless the context clearly indicates otherwise:
AIRPORT ELEVATIONThe highest point of an airport's usable landing area measured in feet above sea level. The airport elevation of the Philadelphia International Airport is 36 feet above sea level.
AIRPORT HAZARDAny structure or object, natural or man-made, or use of land which obstructs the airspace required for flight or aircraft in landing or taking off at an airport or is otherwise hazardous as defined in 14 CFR Part 77 and 74 Pa.C.S.A. § 5102.
AIRPORT HAZARD AREAAny area of land or water upon which an airport hazard might be established if not prevented as provided for in this section and Act 164 of 1984 (Pennsylvania Laws Relating to Aviation).
APPROACH SURFACE (ZONE)An imaginary surface longitudinally centered on the extended runway center line and extending outward and upward from each end of the primary surface. An approach surface is applied to each end of the runway based on the planned approach. The inner edge of the approach surface is the same width as the primary surface and expands uniformly depending on the planned approach. The approach surface zone, as shown on Figure 1, is derived from the approach surface.
CONICAL SURFACE (ZONE)An imaginary surface extending outward and upward from the periphery of the horizontal surface at a slope of 20 feet horizontally to one foot vertically for a horizontal distance of 4,000 feet. The conical surface zone, as shown on Figure 1, is based on the conical surface.
DEPARTMENTPennsylvania Department of Transportation.
FAAFederal Aviation Administration of the United States Department of Transportation.
HEIGHTFor the purpose of determining the height limits in all zones set forth in this section and shown on the Zoning Map, the datum shall be mean sea level elevation unless otherwise specified.
HORIZONTAL SURFACE (ZONE)An imaginary plane 150 feet above the established airport elevation that is constructed by swinging arcs of various radii from the center of the end of the primary surface and then connecting the adjacent arc by tangent lines. The radius of each arc is based on the planned approach. The horizontal surface zone, as shown on Figure 1, is derived from the horizontal surface.
NONCONFORMING USEAny preexisting structure, object of natural growth, or use of land which is inconsistent with the provisions of this section or an amendment thereto.
OBSTRUCTIONAny structure, growth, or other object, including a mobile object, which exceeds a limiting height set forth in this section.
PRIMARY SURFACE (ZONE)An imaginary surface longitudinally centered on the runway, extending 200 feet beyond the end of paved runways or ending at each end of turf runways. The elevation of any point on the primary surface is the same as the elevation of the nearest point on the runway center line. The primary surface zone, as shown on Figure 1, is derived from the primary surface.
RUNWAYA defined area of the airport prepared for landing and takeoff of aircraft along its length.
STRUCTUREAn object, including a mobile object, constructed or installed by man, including but without limitation, buildings, towers, cranes, smokestacks, earth formation and overhead transmission lines.
TRANSITIONAL SURFACE (ZONE)An imaginary surface that extends outward and upward from the edge of the primary surface to the horizontal surface at a slope of seven feet horizontally to one foot vertically (7:1). The transitional surface zone, as shown on Figure 1, is derived from the transitional surface.
TREEAny object of natural growth.