Crab I think you have a mix up in nomenclature.
Yes, and if you are moving backwards within that mass of air ie with a 5 kt tail wind,
Into/down wind is measured relative to the earth - hence the word wind.
Positive/negative airspeed is measured relative to the helicopter and has nothing to do with wind.
Your statement would be correct when "5kt negative airspeed" is substituted for
HF