Mighty Gem, I'm not saying you can't embarrass yourself in a non SAS Gazelle, Loss of Tail Rotor Effectiveness or Yaw divergence is a very real problem in many helicopters. The term Fenestron Stall was supposed to cater for the case where in crosswinds from the right of more than 10 Kts, the laminar flow around the duct of the Fenestron (which allegedly produced a large percentage of the anti-torque thrust)broke down and caused the initial left yaw which started the whole pirouette thing. Many of us were never convinced by this but it was the official RAF and Navy view at the time and at Shawbury we spent a couple of years taxying sideways (crabs after all) into and out of dispersal at 10' which was far more dangerous than the percieved risk of Fenestron Stall.. .Shawn - you are correct of course that the climb descent will happen in any helo, I was only taking issue with your original post stating that it was due to Nr variations. PS thought your book was very good - got any free copies for an old QHI?