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: 

## 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 − 17 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, Paragraph 3 − 1 − 8b2(a), Air Traffic Control, Low Level Wind Shear/Microburst Advisories 

## (a) MICROBURST ALERTS 

