SBAH Mission Footprints
Silverbell Army Heliport’s overall operational footprint includes the following
components:
Noise Impacts
Helipad Imaginary Surfaces
Helipad Accident Potential Zones
Tactical Flight Training Area
Noise
Although helicopter flights at SBAH are a common occurrence, the total number of daily
operations is not high enough to generate noise contours based on DNL annual averages.
There are no Noise Zones II or III that extend outside the boundary of the installation.
However, individual flight operations may result in noise nuisance during flight activities
to and/or from SBAH that may impact property owners on the ground. For this reason,
No Fly Zones have been identified on flight maps, and pilots are advised to fly above
1,000 feet above ground level (AGL) in these areas and to avoid overflight whenever
possible.
SBAH Helipad Imaginary Surfaces
The FAA and DoD have identified certain imaginary surfaces that are used to determine if
structures and facilities constitute a vertical obstruction, relative to the airspace around
runways and helipads. The levels of imaginary surfaces build upon one another and are
designed to eliminate obstructions to air navigation and operations, either natural or
man‐made. The dimension or size of an imaginary surface depends on the type of
runway or helipad around which it is based. For the type of helipads at SBAH, the
following imaginary surfaces are defined:
The primary surface immediately surrounds the landing surface offset by
150 feet and must be kept free of all obstructions not directly required for
airfield operations.
The approach‐departure clearance surface is symmetrically centered on the
extended helipad landing lane, beginning as an inclined plane at the end of the
primary surface and extending for 1,200 feet. The slope of the
approach‐departure clearance surface is 8:1. The width of this surface at the
primary surface is 300 feet, widening uniformly to a width of 600 feet at the end
point.
The transitional surface extends outward and upward at right angles to the
primary surface and extended landing lane at a slope of 2:1. The transitional
surface starts at the lateral edges of the primary surface and the
Pinal County Joint Land Use Study
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