Reactive wind-shear A320
On the B737, Reactive wind-shear was a function of the EGPWS. While the A320 FCOM states WINDSHEAR DETECTION FUNCTION is done by the FAC.
How does the FAC help in windshear detection & how is it different from what the EGPWS does on the B737.
Also why does the FAC need to calculate GW in flight. Why won't it take it from the FMS as in the 737 for calculation of speeds.