Walter:
When you watch a helicopter manoeuvre, you will surely note that it can't change much in terms of aspect, power, anything really without your ears picking up the changes in sound.
Presumably when you watch, or rather hear in this scenario, such a manoeuvre the changes of sound would come as a result of pilot control inputs. If such inputs cannot be made, because the flight controls are jammed, what changes in sound would you expect to hear? I do not say that this accident happened because the flight controls were jammed, Walter, because I do not know, but you stated that the "Ear Witnesses" heard nothing to suggest a control problem. I simply ask what would they hear if there were one?