As a professional helicopter with 30yrs exp ranging from Army support thru' SAR and offshore oil support I would never do a downwind approach unless I absolutely had to. The beauty of the helicopter is that it does not require long strips of concrete that may or may not be oriented into wind, so into wind approaches can nearly always be flown.
In my early days of military life I was taught the gate approach. This was a profile which meant you could approach the gate from any direction and at any speed but you had to pass thru' the gate heading into wind at a certain speed. From memory for the Wessex the gate was 100ft agl and 50kts
If ATC try to make you approach from a certain direction then using the gate approach may save your bacon should your power margin be small or tail rotor authority be marginal.
The performance penalties that occur during a downwind approach should not be taken lightly.
AP
