Downwind Quickstop. Hmmm.
Well of course, you can do the handbreak turn thing - all banked over at low level - lots of fun - but you can also deccelerate straight downwind. It all depends on why you're stopping, and if it really needs to be a quickstop - lots of people simple incorporate the maneuvre into a rushed landing (fast approach > airtaxi > quickstop > land) I think most if not all of us have done that - after all, these things cost money and flying a 10 degree textbook approach into wind after a full pattern takes time.
As far as the aerodynamics goes - the Helicopter has no idea if its going downwind, upwind, crabbing or not - it simply flies relative to the body of air.
The only difference is when and how much power needs to be applied:
When you do a Q stop upwind, you never really get to zero A/S, so all you have to do is lower, then raise as you slow down - obviously your G/S will be lower.
When you do a Q/S downwind, you have to flare all the way down to Zero A/S (requiring more power) THEN you have to start accelerating BACKWARDS to get to Zero G/S.
This is obviously harder because it requires higher power, and downwind your G/S will be quicker, so everything happens much faster.
The key to downwind operations is to fully understand how much power you need at each phase, and to know your that airspeed can already be zero - even though you're nose-up and hurtling towards the pad at 20 kts!
The reason most people 'fall through' and crash is that they flare all the way to zero, then don't recognise it - and keep flaring, nose up, power down, then BANG.
Same reasoning goes for downwind takeoffs - anticipate that your power requirement will go up first, before it goes down, and be smooth...
Last edited by rudestuff; 7th Feb 2007 at 11:30.