Section 16.50  Horizontal Surface

A horizontal surface is a plane 150 feet above the established airport elevation. 

a)         The perimeter of a horizontal surface is constructed by swinging arcs of specified radii from the center of each end of the primary surface of each runway and connecting the adjacent arcs by lines tangent to those arcs.  The radii of each arc is:

1)         5,000 feet for all runways designated as utility or visual; and

2)         10,000 feet for all other runways.

b)         The radius of the arc specified for each end of a runway will have the same arithmetical value.  That value will be the highest value determined for either end of the runway.

c)         When tangents connecting two adjacent 10,000-foot arcs encompass a 5,000-foot arc, the 5,000-foot arc shall be disregarded on the construction of the perimeter of the horizontal surface.

d)         The horizontal surface does not include the approach surface (see Section 16.80) and transitional surfaces (see Section 16.90).

e)         Under Departmental standards, a horizontal surface is defined as a circle (radius 5,000 feet) with the center being the ARP.