Summary of findings from the PIREP-based analyses conducted during the 1988 to 1990 evaluations of TDWR-based and TDWR/LLWAS-based alert services provided to landing/departing pilots

Abstract : The Federal Aviation Administration (FAA) is developing the Terminal Doppler Weather Radar (TDWR). Starting in 1988. the TDWR Program conducted a series of evaluations of a TDWR-based alert service to provide wind shear and microburst alerts to landing and departing pilots. Starting in 1989, a second series of evaluations was initiated involving an integrated alert service consisting of TDWR and the Phase III Low Level Wind Shear Alert System (LLWAS) . Evaluations are expected to continue through 1992. The radio communications between Local Control and (landing and departing pilots were analyzed for 224 of the 323 alert periods that occurred during the 1999 through 1990 and represents one component of the overaLL investigation that took place. A key element of the communications were the pilot reports (PIREPs) of weather-related encounters and observations made during the alert periods. PIREPs were used to: (a) evaluate the accuracy of the issued alerts from the pilot's viewpoint as to the Location and intensity of the wind-related encounters, and (b) identify situations in which pilots reported wind-related encounters that were not provided alert coverage.