ATC EQUIP PROB WIND INDICATORS LLWAS INACCURATE.

Narrative

THE LOW LEVEL WIND SHEAR ALERT SYS (LLWAS) AT THE NASHVILLE ARPT IS VERY INACCURATE. NUMEROUS PLT RPTS COMPLAINING ABOUT THE WINDS THAT ARE ISSUED BY THE CTLRS AT NASHVILLE CAN BE SUBSTANTIATED BY COMPARISON TO THE WIND SOCK AND READINGS ISSUED BY ACFT THAT ARE EFIS EQUIPPED. THE WIND SENSORS INDICATE WINDS OF ONLY 3-4 KTS WHEN IT IS CLOSER TO 20 KTS. THE CTR FIELD WIND SENSOR HAS NOT BEEN REPLACED AFTER THE NEW RWY 2C WAS CONSTRUCTED. EVEN WITH ALL SENSORS OPERATIONAL THE LLWAS DOES NOT GIVE ACCURATE WINDS. THE WINDS DISPLAYED ARE AN AVERAGE OVER 2 MINS. THIS AVERAGE DECREASES THE ACTUAL GUSTS THAT MAY BE RECEIVED. I BELIEVE THAT PLTS WOULD RATHER HAVE A WORST CASE SCENARIO OF A HIGH INSTANTANEOUS GUST THAN AN AVERAGE OF THE WINDS. I HAVE WITNESSED A BE55 NEARLY GO OFF THE RWY WHEN THE WIND SOCK WAS FULL BUT THE LLWAS DISPLAY ONLY INDICATED 3-4 KTS. AN FK100 ALSO COMPLAINED THAT HE WOULD HAVE REQUESTED ANOTHER RWY IF HE KNEW THE WINDS WERE ACTUALLY THAT BAD. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED AFTER HE INFORMED MGMNT A NASA ASRS RPT HAD BEEN FILED THE LLWAS WAS NOTAMED OTS AND THE TWR USED ESTIMATED WIND FROM THE NWS. ANOTHER SENSOR WAS USED AND THE LLWAS WAS RESTORED. RPTR SAID HE WAS INFORMED A CTR FIELD WIND WOULD BE INSTALLED. NO ACTION HAS BEEN FORTH COMING ON A CTR FIELD SENSOR. RPTR FEELS THEY SHOULD HAVE AN ANALOG WIND INDICATOR.