Nick--have to disagree,a little!
I think most early helo`s reached RBS before reaching jack-stall,and usually pitched up and rolled unless you reduced collective-quickly!That said you could demo jack stall by winding RRPM back towards the power-on limit,and you would feel it on the controls( in the S-55 and S-58(WWIND& WX).In the Gazelle, the flight controls were developed so that the a/c could be manoeuvred hard without fear of reaching blade -stall,by designing the hydraulic control system to limit its output,and give a tactile feedback to the pilot that he was at his control limit,or nearly so,and could adjust to compensate,without fear of "stalling",and whilst flying "eye-balls-out"; an admirable aid to any tactical helo pilot,manoeuvring hard even close to the ground.Pity it had to be the pragmatic FFrench who devised the system.!!On the early prototype Gazelles,-001,01,02,the system was superb,you could pull nearly 2 1/2-3G,and as you reached the limit the a/c would roll gently upright,in left and right turns,all nice and safe,even when in-the-weeds."Great",we said," well have a couple of hundred of those".Unfortunately, by the time the a/c got to prod. std., the tailboom had been lowered,the cabin had reduced stiffness,due to the door for the winch,the u/c was now different as you could get grnd. resonance,due to the door and tailboom mods.,and the control -jack manufacturer had changed, and that is why at jack-stall the Gazelle rolls the same way at the limit in both left and right turns!!That said ,if you`ve not tried one ,Nick,go and do it; it`s like getting out of your Olds/Chevy/Plymouth,and getting into a Ferrari,or BMW M-class,or if you may be a Harley-D "biker",get a ride on a Kwik-Kwacker ZX-9RR,or at a lower level,first night with a new mistress- so I`ve been told!!
