A constant horizontal wind will not change your aerodynamic performance (ias, tas, V/s etc) for a given set of input parameters (power+attitude). I WILL change the angle of your descent relative to the ground, so to descend the same altitude in a given distance, you require a higher V/S.
A CHANGING horizontal wind WILL effect your ROD as it is an example of shear.
Winds usually abate with reducing altitude, so you usually have a reducing tail-wind as you descend. This is an example of a positive shear, and will reduce your V/s for a given power/ IAS.
Last edited by Wizofoz; 7th June 2013 at 07:16.