Thread drift.
I was on the Gazelle IFTU at Middle Wallop and as far as I know nobody had any flying problems with the fenestron despite performing prolonged max speed spot turns in either direction. I also don't recall any SAS on the IFTU aircraft. If that was the case then why and when was SAS fitted, and could that have caused any of the subsequent problems? I thought the Gazelle was a joy to fly but after flying/instructing on Hillers and Whirlwind 7's (where controlling RRPM with the collective twistgrip required constant attention) I felt that the ease of flying the Gazelle could introduce accidents caused by overconfidence rather than mechanical problems as had been experienced in the previous generation of helicopters.