ACR X GPWS WHEN ISSUED DSCNT TO MVA. EVASIVE ACTION CLB.

Narrative

WHILE BEING VECTORED FOR THE ILS 34 AT AVL; ON THE L DOWNWIND AT 5100 FT MSL; HDG 160 DEGS; WE WERE GIVEN A CLRNC TO 'TURN L TO 010 DEGS TO INTERCEPT THE LOC; MAINTAIN 4400 FT UNTIL ESTABLISHED; CLRED FOR THE ILS 34 APCH.' DURING THE TURN; APPROX 090 DEG HDG; AND DSNDING THROUGH 4800 FT MSL; WE RECEIVED A 'TERRAIN-PULL UP' WARNING FROM THE GND PROX WARNING SYS. WE ADJUSTED THE RATE OF DSCNT FROM NEARLY 1000 FPM TO 500 FPM AND LEVEL AT 4400 FT MSL WITH NO FURTHER WARNINGS. ILS APCH AND LNDG WERE NORMAL. I COMMENTED TO THE FO ABOUT THE 2 ANTENNAS STICKING OUT OF THE CLOUDS (APPROX 15 MI SSE OF AVL AT 5049 FT AND 4240 FT). WE ENTERED THE CLOUDS WHILE DSNDING TO 4400 FT MSL. LATER I SPOKE TO THE TWR CTLR ABOUT THE INCIDENT AND GAVE HIM THE DETAILS. HE TOLD ME XY ACR WAS ALSO EXPERIENCING THESE PROBS AND THAT AVL ATC WAS COLLECTING AS MUCH INFO AS POSSIBLE FROM THESE EVENTS FOR A POSSIBLE CHANGE IN THEIR MINIMUM VECTORING ALT IN THAT AREA. (APPROX 15 MI SSE OF AVL ON THE SUG VOR 233 DEG RADIAL 18-25 DME.) ALSO; TO ME; IT IS NOW UNCLR AS TO WHETHER OUR CLRED ALT WAS 4600 FT OR 4400 FT; BUT I BELIEVE IT TO BE THE LATTER. THAT ALT CORRESPONDS WITH THE INITIAL APCH ALT FOR ILS 34. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: FACILITY ATM IS AWARE OF THE PROB. HE STATED HE INVESTIGATED THE GPWS INCIDENTS AND THE CTLR HAD DSNDED THE ACFT TO THE CORRECT MVA. ATM STATED HE WAS GOING TO HAVE FIFO FLT CHK THE MINIMUM VECTORING ALTITUDES. ANALYST STATED IT WAS PROBABLY SET OFF BY THE ACFT DSCNT RATE INTO RISING TERRAIN.