During fast and furious mustering operations in an R22 it is possible to experience a flight condition that I am not really sure how to explain, I guess it is Blade stalling but there is no loss of RPM, just an onset of shuddering and severe loss of lift. It is easily fixed by reducing the amount of control input but if allowed to continue will end up shuddering onto the ground with no loss of RPM although I have only heard of it happening in severe operations close to the ground so it’s all over pretty quickly, back off the control input and the problem is gone. To encounter it proceed at 60kts+ straight and level or in a dive, introduce the cyclic input first quite strongly so that the airframe is still travelling in the same plane but with the disc in a flared attitude obviously intending to throttle off and control RRPM with collective and if you are able to get a severe enough flare and you are fast enough (60+) it will happen. If more collective is input after the shuddering has started it gets worse. I learned to fly around it by introducing a slight amount of collective first before the cyclic and no problem, basically same manoeuvre, same result. I guess I am probably just a rough pilot but I have 18,000 hrs mustering in R22’s so plenty of time to practice. So the main requirements are
1/ Speed 60kts +
2/ Severe flare of the disc with the airframe still in the same plane
3/ Not much Collective pitch input
Would someone like to comment