[Ord. 01-09-18-1, 9/18/2001, § 2101]
AIRPORT
Doylestown Airport.
AIRPORT ELEVATION
The highest point of the airport's usable landing area, measured in feet from sea level, which is 394 feet above mean sea level.
AIRPORT HAZARD
Any structure or object, natural or man-made, or use of land which obstructs the airspace required for flight of aircraft in landing or taking off at an airport or is otherwise hazardous to the 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.
APPROACH SURFACE
A surface longitudinally centered on the extended runway center line, extending outward and upward from the end of the primary surface and at the same slope as the approach height limitation slope set forth in this Part. In plan, the perimeter of the approach surface coincides with the perimeter of the approach zone.
APPROACH, TRANSITIONAL, HORIZONTAL AND CONICAL ZONES
These zones as set forth in this Part.
CONICAL SURFACE
A surface extending outward and upward from the periphery of the horizontal surface at a slope of 20 to 1 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 Part and shown on the Airport Zone 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, in plan, coincides with the perimeter of the horizontal zone.
LARGER THAN UTILITY RUNWAY
A runway that is constructed for and intended to be used by propeller driven aircraft of greater than 12,500 pounds maximum gross weight and jet-powered aircraft.
NONPRECISION INSTRUMENT RUNWAY
A runway having an existing instrument approach procedure utilizing air navigation facilities with only horizontal guidance, or area type navigation equipment, for which a straight-in nonprecision instrument approach procedure has been approved or planned.
OBSTRUCTION
Any structure, growth or other object, including a mobile object, which exceeds a limiting height set forth in this Part.
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. For military runways or 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 this Part. The elevation of any point on the primary surface is the same as the elevation of the nearest point on the runway center line.
RUNWAY
A defined area on an airport prepared for landing and takeoff of aircraft along its length.
STRUCTURE
For the purposes of this Part, an 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 SURFACES
These surfaces extend outward at 90° angles to the runway center line and the runway center line 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. Transitional surfaces for those portions of the precision approach surfaces, which project through and beyond the limits of the conical surface, extend a distance of 5,000 feet measured horizontally from the edge of the approach surface and at 90° angles to the extended runway center line.
TREE
Any object of natural growth.