Interestingly enough, I have found that when working the 412 EP / HP very heavy and in light winds ( not underslung) it is possible to fly the aircraft away with a right quartering tail wind, at a considerably reduced Mast torque. You do need a drop down height available, to gain airspeed, so I am talking platforms and the like. I call it putting the wind in your back right pocket.
Others I know have used the technique with success, but as we are mere drivers none of us have an idea as to WHY it works.
I know there is added exposure of risk in using drop down for airspeed, being near downwind, so this requires judgement, however it will get you away when very heavy and hot. ( Im not after a slagging from so called experts here on the technique, but does anyone actually know why it works?)