RavenX
You often require less power to hover downwind than into-wind. It depends upon the windspeed. Here are a couple of reasons why:
1. When into-wind the main rotor tip vortices (and downwash) will be blown rearwards and can interfere with the tail-rotor. This 'dirty' air can decrease the efficiency of the T/R.
2. The downwash of the rotor system pushes down on the fuselage and creates an apparent increase in weight. When hovering into wind, more of the aircraft structure is subject to downwash than when hovering downwind.
Finally, don't hover exactly downwind but allow a slight x-wind component to try to weather-cock the aircraft back into wind. Assuming you choose the correct side, you'll need a load of non-power pedal to hold the heading and consequently use less power.
Robbo Jock.
Having flown the R22 a bit, I wouldn't dream of trying to deduce what goes on with its tiddly tail rotor; I just know it doesn't behave as predictably as bigger, 'proper' helicopters when subjected to a x-wind. But that said, I know that it takes no more power to hover down-wind than it does into-wind. Now if we're talking into-wind approach versus downwind approach; that's a whole different story..........
J