时间：2011-04-18 00:52来源：蓝天飞行翻译 作者：航空 点击：次
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7.1.50 Meteorology FIG 7.1.17 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 Many of these systems have been replaced by new TDWR and WSP technology.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. 3. Terminal Doppler Weather Radar (TDWR). (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 7.1.17 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 Meteorology 7.1.51 gust front detection, storm growth and decay, microburst prediction, and turbulence detection. (c)TDWR also provides a geographical situation display (GSD) for supervisors and traffic management specialists for planning purposes. The GSD displays (in color) 6 levels of weather (precipitation), gust fronts and predicted storm movement(s). This data is used by the tower supervisor(s), traffic management specialists and controllers to plan for runway changes and arrival/departure route changes in order to both reduce aircraft delays and increase airport capacity. 4. Weather System Processor (WSP). (a)The WSP provides the controller, supervi-sor, traffic management specialist, and ultimately the pilot, with the same products as the terminal doppler weather radar (TDWR) at a fraction of the cost of a TDWR. This is accomplished by utilizing new technologies to access the weather channel capabili-ties of the existing ASR.9 radar located on or near the airport, thus eliminating the requirements for a separate radar location, land acquisition, support facilities and the associated communication landlines and expenses. (b)The WSP utilizes the same RBDT display as the TDWR and LLWAS, and, just like TDWR, also has a GSD for planning purposes by supervisors, traffic management specialists and controllers. The WSP GSD emulates the TDWR display, i.e., it also depicts 6 levels of precipitation, gust fronts and predicted storm movement, and like the TDWR GSD, is used to plan for runway changes and arrival/depar-ture route changes in order to reduce aircraft delays and to increase airport capacity. (c)This system is currently under develop-ment and is operating in a developmental test status at the Albuquerque, New Mexico, airport. When fielded, the WSP is expected to be installed at 34 airports across the nation, substantially increasing the safety of the American flying public. 5. Operational aspects of LLWAS, TDWR and WSP. To demonstrate how this data is used by both the controller and the pilot, 3 ribbon display examples and their explanations are presented: (a) MICROBURST ALERTS EXAMPLE. This is what the controller sees on his/her ribbon display in the tower cab. 27A MBA 35K. 2MF 250 20 NOTE. (See FIG 7.1.18 to see how the TDWR/WSP determines the microburst location). This is what the controller will say when issuing the alert. PHRASEOLOGY. RUNWAY 27 ARRIVAL, MICROBURST ALERT, 35 KT LOSS 2 MILE FINAL, THRESHOLD WIND 250 AT 20. In plain language, the controller is telling the pilot that on approach to runway 27, there is a microburst alert on the approach lane to the runway, and to anticipate or expect a 35 knot loss of airspeed at approximately 2 miles out on final approach (where it will first encounter the phenomena). With that information, the aircrew is forewarned, and should be prepared to apply wind shear/microburst escape procedures should they decide to continue the approach. Additionally, the surface winds at the airport for landing runway 27 are reported as 250 degrees at 20 knots. NOTE. Threshold wind is at pilot’s request or as deemed appropriate by the controller. REFERENCE. FAA Order JO 7110.65, Air Traffic Control, Low Level Wind Shear/Microburst Advisories, Paragraph 3.1.8b2(a). Meteorology 7.1.52 FIG 7.1.18 Microburst Alert (b) WIND SHEAR ALERTS EXAMPLE. This is what the controller sees on his/her ribbon display in the tower cab. 27A WSA 20K. 3MF 200 15 NOTE. (See FIG 7.1.19 to see how the TDWR/WSP determines the wind shear location). This is what the controller will say when issuing the alert. PHRASEOLOGY. RUNWAY 27 ARRIVAL, WIND SHEAR ALERT, 20 KT LOSS 3 MILE FINAL, THRESHOLD WIND 200 AT 15. In plain language, the controller is advising the aircraft arriving on runway 27 that at about 3 miles out they can expect to encounter a wind shear condition that will decrease their airspeed by 20 knots and possibly encounter turbulence. Additionally, the airport surface winds for landing runway 27 are reported as 200 degrees at 15 knots. |
