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FIG 4

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Effects of a Geographical Constraint on a Runway's Declared Distances

NOTE

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A runway's RSA begins a set distance prior to the threshold and will
extend a set distance beyond the end of the runway

depending on the runway's design criteria. If these required lengths
cannot be achieved, the ASDA and/or LDA will be

reduced as necessary to obtain the required lengths to the extent
practicable.

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7.  Low Level Wind Shear/Microburst Detection Systems

Low Level Wind Shear Alert System (LLWAS), Terminal Doppler Weather
Radar (TDWR), Weather Systems

Processor (WSP), and Integrated Terminal Weather System (ITWS) display
information on hazardous wind

shear and microburst activity in the vicinity of an airport to air
traffic controllers who relay this information to

pilots.

a.

LLWAS provides wind shear alert and gust front information but does not
provide microburst alerts. The

LLWAS is designed to detect low level wind shear conditions around the
periphery of an airport. It does not detect

wind shear beyond that limitation. Controllers will provide this
information to pilots by giving the pilot the

airport wind followed by the boundary wind.

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Airport Operations