I think the Jack stall demo is no longer taught officially on the UK Gazelle, but I was certainly demo'd one and tried one for myself when I went through.
Vne dive and pull up hard till it tried to flick itself on its back. Lots of fun.
Got to say though, having flown a large number of Helicopters from Seakings to Seahawks Squirrels to Hips, you can't beat the Gazelle. The French do make very fine Helicopters, (even if they always do have a flaw or two to keep you on your toes!)
A true gentlemans sportscar.
You dont fly it, you strap it on.