8/15/19 3/15/07 1/30/20 AIM  7110.65R CHG 2 AIM FIG 7 − 1 − 16 Warning Boxes  (b) LLWAS was fielded in 1988 at 110 air- ports across the nation. Many of these systems have been replaced by new TDWR and WSP technology. Eventually all LLWAS systems will be phased out; however, 39 airports will be upgraded to the LLWAS − NE (Network Expansion) system, which employs the very latest software and sensor technology. The new LLWAS − NE systems will not only provide the controller with wind shear warnings and alerts, including wind shear/microburst detection at the airport wind sensor location, but will also provide the location of the hazards relative to the airport runway(s). It will also have the flexibility and capability to grow with the airport as new runways are built. As many as 32 sensors, strategically located around the airport and in relationship to its runway configuration, can be accommodated by the LLWAS − NE network. (a) TDWRs are being deployed at 45 loca- tions across the U.S. Optimum locations for TDWRs are 8 to 12 miles off of the airport proper, and designed to look at the airspace around and over the airport to detect microbursts, gust fronts, wind shifts and precipitation intensities. TDWR products advise the controller of wind shear and microburst events impacting all runways and the areas $^{1}$/$_{2}$ mile on either side of the extended centerline of the runways out to 3 miles on final approach and 2 miles out on departure. (FIG 7 − 1 − 16 is a theoretical view of the warning boxes, including the runway, that the software uses in determining the location(s) of wind shear or microbursts). These warnings are displayed (as depicted in the examples in subparagraph 5) on the RBDT. (b) It is very important to understand what TDWR does NOT DO: (1) It DOES NOT  warn of wind shear outside of the alert boxes (on the arrival and departure ends of the runways); (2) It DOES NOT  detect wind shear that is NOT a microburst or a gust front; (3) It DOES NOT  detect gusty or cross wind conditions; and (4) It  DOES NOT  detect turbulence. However, research and development is continuing on these systems. Future improvements may include such areas as storm motion (movement), improved 3. Terminal Doppler Weather Radar (TD- WR). Meteorology 7 − 1 − 50