a. 250 fct for utility runways having visual
appr *,s only.
b. 500 1i L for utility runways having non-precision
instrument approaches.
c. For other than utility runways the width is:
(1) 500 feetfor visual runways having only visual
approaches.
(2) 500 feet for non-precision instrument runways
having visibility minimums greater than three-
fourths statute mile.
(3) 1,000 feet for a non-precision instrument
approach with visibility m1inimuims as low a;S
three-fourths statute mile, and for precision
instrument runways.
2. Ilorizojtital Zone A horizontal plane 150 feet above the
established airport elevation, encompassing the runways,
primary zones and transitional zones, the perimeter of
which is constructed by swinging arcs of specified radii
from the center of each end of the primary surface of
each runway of each airport and connecting the adjacent
arcs by lines tangent to those arcs. The radius of each
arc is:
a. 5,000 feet for all runways designated as utility or
visual approaches only.
b. 10,000 feet for all other runways.
The radius of the arc specified for each end of a runway
shall have the same arithmetical value. That value will
be the highest determined for either end of the runway.
When a 5,000 foot arc is encompassed by tangents
connecting two adjacent 10,000 foot arcs, the 5,000 foot
arc shall be disregarded. No structure will be permitted
in the horizontal zone that is higher than 150 feet above
the established airport elevation.
3. Conical Zone The area extending outward and upward from
the periphery of the horizontal zone for a distance of
4,000 feet on a slope of 20 to 1. Ile ight limitatiLn::
for structures in the conical zone are 150 feet above
airport eleva tion at the inner boundary of Llthe :zon witii
permitted height increasing one foot vertically for
every twenty feet of horizontal distance outward from the
inner boundary of the zone to a height of 350 feet above
airport elevation at the outer boundary of the zone.
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