Originally Posted by
n5296s
Why are you so certain? Not saying you're wrong, just curious? It was way beyond Vne (most likely)..
The helicopter doesn't self destruct and fall out of the sky as you pass on to the wrong side of Vne. Vne is a number that the flight test guys and engineers come up with, with significant safety margins built in, to keep you on the right side of the fatigue life calculations so your flight safety critical bits don't wear out or break before they are due to be time-expired. The S76 will easily fly through Vne and keep flying, but the wear and tear on the rotor system and tail boom (and hydraulic servo actuators) goes exponential big time. Therefore compromising the component fatigue life. If that helicopter was doing 180 (and I'd be surprised if it was), and even if it was heavy, and even if it was cutting some bank angle, the retreating blade would not be stalled. And in any event, with the onset of retreating blade stall the tendency is for the nose of the helicopter to pitch up slightly (in addition to roll) and reduce the angle of attack of the blades, thus self-correcting the onset of the stall. I really don't think RBS has anything to do with the accident outcome.